Since 1.19.30 (and still in 1.19.31 Hotfix) I've been seeing a severe performance degradation where chunks do not fully load and remain as empty spaces in the world.  It can take upto a minute for these areas to fully load, sometimes I need to leave the area and return for it to correctly load.  While the chunks are incomplete, the player is also unable to enter that area and is blocked as if hitting an invisible wall.

I've also noticed this performance degradation when exploring and moving around the world too (specifically when using an Elytra) where the player will just stop moving in the world & be prevented from going further.  This worsens the more the player explores or moves around the world through unloaded chunks.

This is more apparent when logging into the server, as the world can take a long time to load.

Checking the server load, performance and IO/Network throughput, while these chunks are unloaded, there is very little load on the host and no IO or Network bottlenecks.

My BDS Server stores all world data on a remote NFS Share, however I have moved the world data to local storage to rule out any networking issues, and this made no difference at all.

There are no corruption warnings in the terminal output, and the only log entries are the standard player joined/left and auto compaction messages.

Performance degradation is also the same regardless of platform used to play (PC/Switch/PS4).  Performance on pre-1.19.30 server is absolutely fine.