Describe the bug
when traveling through dimensions every backpack that is placed on the ground loses its inventory.

To Reproduce
Steps to reproduce the behavior:

1. place down a backpack with items in its inventory.
2. pass through a nether / end portal.
3. the inventory of the backpack is empty.

Expected behavior
the inventory suppose be kept as before the traveling through dimensions.

Screenshots
If applicable, add screenshots to help explain your problem.

Required informations (please complete the following information):

• Mod version: [e.g. 1.18.1 - 7.0.1]

Additional context
Add any other context about the problem here.

has happened to me with TravelersBackpack-1.18.1-7.0.0 with Forge version 39.0.19 as well.

The first time I had died, spawned back at spawn, then went back to claim my backpack and it was empty (no portal hopping)

second time was last night when entering the nether for the first time in this world, placed it down to keep it safe, returned and all my stuff was gone that was within it.

I can't reproduce issue on 7.0.1, does it happen?

I updated our server to 7.0.1 and tried to reproduce it, but also could not.
Reproducing it in 7.0.0 was pretty easy though. It seems that when the backpack is left in unloaded chunks the inventory would get wiped, which would explain why hopping through portals would delete the items.
Tested with a chunkloader active, and not active, and it would only delete items when the chunks would unload.

Gonna keep an eye on it and report back if it happens again

Well, this issue is fixed in 7.0.1. So it does not happen anymore?