Large DelayedPickupEvent backlog

[bluelightning32]

Modpack: DD&SS v 5.6a
SpongeForge: spongeforge-1.12.2-2838-7.1.7-RC3785.jar
AutoPickup: AutoPickup-1.12-2.5.1.jar
Tiquality: Tiquality-THIN-1.12.2-GAMMA-1.4.3.jar

I noticed a high tick time on my server without many players logged in. LagGoggles showed that all the time was spent inside of AutoPickup:

I collected an hprof. It showed there were 12235767 delayed events.

The first 10 or so I checked were all for the same location. I went to that location and it was just part of the floor.

Most were for this player. This player was AFK and starving on top of a sanguine bush earlier, but was not doing anything unusual when I collected the hprof and investigated.
https://cdn.discordapp.com/attachments/529156981399748610/614744474941390858/unknown.png

All the entries I see in DelayedPickupEvent::delays point to an Integer for value 1.

The player has tried logging out and back in, and it didn't help. I couldn't find anything helpful in debug.log. I run 4 different nodes of DD&SS. This issue has only showed up in one of them so far.