Issue seems to be on multiplayer servers only.
How to replicate:
Join a multiplayer server (I use minehut)
Have keepInventory gamerule active
Go to the Nether or the End with items
Die
You lose all of your items
Issue seems to be on multiplayer servers only.
How to replicate:
Join a multiplayer server (I use minehut)
Have keepInventory gamerule active
Go to the Nether or the End with items
Die
You lose all of your items
You seem to be using a non-vanilla server. Try replicating the bug with a vanilla server.