[enterprise-3.10] Re-add 3.10 APB known issue

release_notes/ocp_3_10_release_notes.adoc

@@ -1946,6 +1946,34 @@ xref:../upgrading/downgrade.adoc#install-config-downgrade[Downgrading OpenShift]
 documentation, an issue was found with the steps for restoring etcd. The
 document has since been updated and this is no longer an issue.
 
+* {product-title} 3.10 adds the ability for multiple instances of an APB to be
+invoked in the same namespace. This new ability requires relying on a globally
+unique identifier (GUID) for each instance. While instances deployed by an 3.9
+version of an APB lack the GUID, 3.10 APBs require it.
++
+--
+A 3.10 APB is unable to manage a 3.9 deployed service because it lacks the
+newly required GUID. This causes clusters upgraded from 3.9 to 3.10 to result in
+an error if an application that was previously deployed on 3.9 is then
+deprovisioned from 3.10 APB.
+
+There are two workarounds to this issue currently:
+
+* After the cluster upgrade to 3.10 has completed, delete the namespace of the
+application and recreate it. This will use the 3.10 version of the APB and
+function as expected.
+
+* Modify the configuration of the OpenShift Ansible broker to remain on the 3.9
+version of APBs. This is not recommended, however, as it has the downside of the
+broker using 3.10 code while the APBs use the older 3.9 version:
+
+.. Follow the procedure in
+xref:../install_config/oab_broker_configuration.adoc#install-config-oab-modifying[Modifying the OpenShift Ansible Broker Configuration] to change the label to `v3.9`.
+.. Run the `apb bootstrap` command to bootstrap the broker and relist the catalog.
+
+(link:https://bugzilla.redhat.com/show_bug.cgi?id=1586108[*BZ#1586108*])
+--
+
 [[ocp-310-asynchronous-errata-updates]]
 == Asynchronous Errata Updates