0. ALWAYS PROVIDE INFORMATION ABOUT MODLOADER (Fabric / Forge) AND MOD VERSION (For Example 1.19.2-8.2.10)

Forge 47.4.0 - 1.20.1
travelersbackpack-forge-1.20.1-9.1.39

1. Describe the bug

When I hold the backpack in hand I experience extreme lag and FPS go down to 0. I'm using a custom modpack. Here's a spark profile: https://spark.lucko.me/VJBEOhnOW9

I think it happens after placing any item inside the backpack, and it persists after emptying it.
Here's the latest log containing what I got after using /data get entity @s SelectedItem: https://www.mediafire.com/file/ne804ptaueqgotm/latest.log/file

2. Write steps to reproduce the bug

I don't know. Everything was working great in the beginning but recently the issue started to happen :(

Can you provide modpack code for tests?

Sure. Here's the modpack: https://mega.nz/file/D11V1b4T#yZNbX4PLz6OrBJp5WF0daPe5xxjjO5vjc_kRL0n7EmU

Unfortunately I'm unable to reproduce the issue, holding backpack in hand with some items inside doesnt cause any framerate issues