To reproduce:

• Fly away from the spawn region.
• No other players nearby (I tested while being alone on the server).
• No plugins required, except one that simply logs the chunk loading and unloading: https://pastebin.com/UhAnUz7z (the entity related code can be ignored)
• Die, eg. via \kill @a
• Observe in the log: The chunk containing the player gets constantly unloaded and then loaded again while the player is in the death screen.

I don't know whether this is also the case in vanilla.

I don't believe this is caused by the logging plugin.

I noticed this while debugging some issue with one of my plugins, which spawns entities during chunk load and removes them again on chunk unload. This frequent loading and unloading would then cause the chunk to accumulate 'dead' entities (entities which have been marked for removal, but did not get removed yet), causing some issue in combination with a plugin which tries to limit mob counts per chunk (and which does not account for the chunk containing large numbers of 'dead' entities).

This plugin compatibility issue can probably be resolved, however I wonder whether its root cause (the indefinite spamming of chunk loading and unloading) is intended or can be considered a bug.