I have the latest Neoforge version of the mod on 1.21.1
I have Travellers backpack as well as Sophisticated backpack

I have the Travellers backpack bound to "K" to open - upon death, I can't open the backpack through the bound key anymore
Unequpping, closing the inventory, then equpping it again seems to do the trick, but not always.

I tried both options, when backpack remains equipped on death as well as put in the grave.
Besides this issue, the backpack behaves fine - items are intact, the backpack is not lost.

The only line I see in the logs, unsure if it's related, is this:

[18Feb2025 22:12:50.193] [Render thread/ERROR][io.wispforest.accessories.networking.client.SyncEntireContainer/]: Unable to Sync Container Data for a given Entity as it is null on the Client! [EntityId: 22524]

The event log is:
DEATH
I hit respawn, the line above appears (EntityId is always different)
And then I get the coords of the grave