diff --git a/deps/rabbit/src/rabbit_fifo.erl b/deps/rabbit/src/rabbit_fifo.erl
index 54b28f8a31d4..83ff3c8edafa 100644
--- a/deps/rabbit/src/rabbit_fifo.erl
+++ b/deps/rabbit/src/rabbit_fifo.erl
@@ -1172,7 +1172,9 @@ query_messages_total(State) ->
     messages_total(State).
 
 query_processes(#?STATE{enqueuers = Enqs, consumers = Cons0}) ->
-    Cons = maps:fold(fun({_, P}, V, S) -> S#{P => V} end, #{}, Cons0),
+    Cons = maps:fold(fun(_, ?CONSUMER_PID(P) = V, S) ->
+                             S#{P => V}
+                     end, #{}, Cons0),
     maps:keys(maps:merge(Enqs, Cons)).
 
 
diff --git a/deps/rabbit/test/rabbit_fifo_int_SUITE.erl b/deps/rabbit/test/rabbit_fifo_int_SUITE.erl
index 1a8d4d7adc9c..9d5d3695684c 100644
--- a/deps/rabbit/test/rabbit_fifo_int_SUITE.erl
+++ b/deps/rabbit/test/rabbit_fifo_int_SUITE.erl
@@ -93,8 +93,8 @@ basics(Config) ->
     ConsumerTag = UId,
     ok = start_cluster(ClusterName, [ServerId]),
     FState0 = rabbit_fifo_client:init([ServerId]),
-    {ok, FState1} = rabbit_fifo_client:checkout(ConsumerTag, {simple_prefetch, 1},
-                                                #{}, FState0),
+    {ok, _, FState1} = rabbit_fifo_client:checkout(ConsumerTag, {simple_prefetch, 1},
+                                                   #{}, FState0),
 
     rabbit_quorum_queue:wal_force_roll_over(node()),
     % create segment the segment will trigger a snapshot
@@ -184,7 +184,7 @@ duplicate_delivery(Config) ->
     ServerId = ?config(node_id, Config),
     ok = start_cluster(ClusterName, [ServerId]),
     F0 = rabbit_fifo_client:init([ServerId]),
-    {ok, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
+    {ok, _, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
     {ok, F2, []} = rabbit_fifo_client:enqueue(ClusterName, corr1, msg1, F1),
     Fun = fun Loop(S0) ->
             receive
@@ -219,7 +219,7 @@ usage(Config) ->
     ServerId = ?config(node_id, Config),
     ok = start_cluster(ClusterName, [ServerId]),
     F0 = rabbit_fifo_client:init([ServerId]),
-    {ok, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
+    {ok, _, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
     {ok, F2, []} = rabbit_fifo_client:enqueue(ClusterName, corr1, msg1, F1),
     {ok, F3, []} = rabbit_fifo_client:enqueue(ClusterName, corr2, msg2, F2),
     {_, _, _} = process_ra_events(receive_ra_events(2, 2), ClusterName, F3),
@@ -272,7 +272,7 @@ detects_lost_delivery(Config) ->
     F000 = rabbit_fifo_client:init([ServerId]),
     {ok, F00, []} = rabbit_fifo_client:enqueue(ClusterName, msg1, F000),
     {_, _, F0} = process_ra_events(receive_ra_events(1, 0), ClusterName, F00),
-    {ok, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
+    {ok, _, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F0),
     {ok, F2, []} = rabbit_fifo_client:enqueue(ClusterName, msg2, F1),
     {ok, F3, []} = rabbit_fifo_client:enqueue(ClusterName, msg3, F2),
     % lose first delivery
@@ -301,9 +301,9 @@ returns_after_down(Config) ->
     Self = self(),
     _Pid = spawn(fun () ->
                          F = rabbit_fifo_client:init([ServerId]),
-                         {ok, _} = rabbit_fifo_client:checkout(<<"tag">>,
-                                                               {simple_prefetch, 10},
-                                                               #{}, F),
+                         {ok, _, _} = rabbit_fifo_client:checkout(<<"tag">>,
+                                                                  {simple_prefetch, 10},
+                                                                  #{}, F),
                          Self ! checkout_done
                  end),
     receive checkout_done -> ok after 1000 -> exit(checkout_done_timeout) end,
@@ -382,7 +382,7 @@ discard(Config) ->
     _ = ra:members(ServerId),
 
     F0 = rabbit_fifo_client:init([ServerId]),
-    {ok, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10},
+    {ok, _, F1} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10},
                                            #{}, F0),
     {ok, F2, []} = rabbit_fifo_client:enqueue(ClusterName, msg1, F1),
     F3 = discard_next_delivery(ClusterName, F2, 5000),
@@ -405,8 +405,8 @@ cancel_checkout(Config) ->
     ok = start_cluster(ClusterName, [ServerId]),
     F0 = rabbit_fifo_client:init([ServerId], 4),
     {ok, F1, []} = rabbit_fifo_client:enqueue(ClusterName, m1, F0),
-    {ok, F2} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10},
-                                           #{}, F1),
+    {ok, _, F2} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10},
+                                              #{}, F1),
     {_, _, F3} = process_ra_events(receive_ra_events(1, 1), ClusterName, F2,
                                    [], [], fun (_, S) -> S end),
     {ok, F4} = rabbit_fifo_client:cancel_checkout(<<"tag">>, F3),
@@ -424,7 +424,7 @@ lost_delivery(Config) ->
     {_, _, F2} = process_ra_events(
                    receive_ra_events(1, 0), ClusterName, F1, [], [],
                    fun (_, S) -> S end),
-    {ok, F3} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F2),
+    {ok, _, F3} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 10}, #{}, F2),
     %% drop a delivery, simulating e.g. a full distribution buffer
     receive
         {ra_event, _, Evt} ->
@@ -449,6 +449,7 @@ lost_delivery(Config) ->
     ok.
 
 credit_api_v1(Config) ->
+    meck:expect(rabbit_feature_flags, is_enabled, fun (_) -> false end),
     ClusterName = ?config(cluster_name, Config),
     ServerId = ?config(node_id, Config),
     ok = start_cluster(ClusterName, [ServerId]),
@@ -458,7 +459,7 @@ credit_api_v1(Config) ->
     {_, _, F3} = process_ra_events(receive_ra_events(2, 0), ClusterName, F2),
     %% checkout with 0 prefetch
     CTag = <<"my-tag">>,
-    {ok, F4} = rabbit_fifo_client:checkout(CTag, credited, #{}, F3),
+    {ok, _, F4} = rabbit_fifo_client:checkout(CTag, {credited, 0}, #{}, F3),
     %% assert no deliveries
     {_, _, F5} = process_ra_events(receive_ra_events(), ClusterName, F4, [], [],
                                    fun
@@ -505,9 +506,9 @@ credit_api_v2(Config) ->
     CTag = <<"my-tag">>,
     DC0 = 16#ff_ff_ff_ff,
     DC1 = 0, %% = DC0 + 1 using 32 bit serial number arithmetic
-    {ok, F4} = rabbit_fifo_client:checkout(
+    {ok, _, F4} = rabbit_fifo_client:checkout(
                  %% initial_delivery_count in consumer meta means credit API v2.
-                 CTag, credited, #{initial_delivery_count => DC0}, F3),
+                 CTag, {credited, DC0}, #{}, F3),
     %% assert no deliveries
     {_, _, F5} = process_ra_events(receive_ra_events(), ClusterName, F4, [], [],
                                    fun
@@ -609,7 +610,7 @@ test_queries(Config) ->
               exit(ready_timeout)
     end,
     F0 = rabbit_fifo_client:init([ServerId], 4),
-    {ok, _} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 1}, #{}, F0),
+    {ok, _, _} = rabbit_fifo_client:checkout(<<"tag">>, {simple_prefetch, 1}, #{}, F0),
     {ok, {_, Ready}, _} = ra:local_query(ServerId,
                                          fun rabbit_fifo:query_messages_ready/1),
     ?assertEqual(1, Ready),
@@ -637,8 +638,8 @@ dequeue(Config) ->
     {ok, F2_, []} = rabbit_fifo_client:enqueue(ClusterName, msg1, F1b),
     {_, _, F2} = process_ra_events(receive_ra_events(1, 0), ClusterName, F2_),
 
-    % {ok, {{0, {_, msg1}}, _}, F3} = rabbit_fifo_client:dequeue(ClusterName, Tag, settled, F2),
-    {ok, _, {_, _, 0, _, msg1}, F3} = rabbit_fifo_client:dequeue(ClusterName, Tag, settled, F2),
+    {ok, _, {_, _, 0, _, msg1}, F3} =
+        rabbit_fifo_client:dequeue(ClusterName, Tag, settled, F2),
     {ok, F4_, []} = rabbit_fifo_client:enqueue(ClusterName, msg2, F3),
     {_, _, F4} = process_ra_events(receive_ra_events(1, 0), ClusterName, F4_),
     {ok, _, {_, _, MsgId, _, msg2}, F5} = rabbit_fifo_client:dequeue(ClusterName, Tag, unsettled, F4),
@@ -698,7 +699,7 @@ receive_ra_events(Acc) ->
     end.
 
 process_ra_events(Events, ClusterName, State) ->
-    DeliveryFun = fun ({deliver, _, Tag, Msgs}, S) ->
+    DeliveryFun = fun ({deliver, Tag, _, Msgs}, S) ->
                           MsgIds = [element(1, M) || M <- Msgs],
                           {S0, _} = rabbit_fifo_client:settle(Tag, MsgIds, S),
                           S0