Mods: Sophisticated Backpacks | Simply Swords (Any mod with 2 handed weapons, this is an example, but I do not know what the base mod is)

Describe the bug
Refill upgrade, when set to send to the offhand slot, will delete items when holding a two handed tool/weapon.

To Reproduce
Steps to reproduce the behavior:

1. Open backpack
2. Fill backpack with items
3. Click on 'Advanced Refill' tab
4. Set the item to be refilled to the off hand
5. Put bag in inventory (if not already so)
6. Hold 2 handed weapon and quickly open bag
7. See items drain into nowhere

Expected behavior
Items do not refill to a non-existent offhand slot

Screenshots
Video:
(https://drive.google.com/file/d/1jk4bQ2OZng9D0xaeume5GWM3DGMQYatd/view?usp=sharing)

Screenshots (if you are unable to watch the video for some reason):

Versions
Mod version: 1.19.2-3.20.2.1035

I don't really support 1.19.2 with anything but super critical fixes and I wouldn't really consider this that because you can easily avoid it. But took a quick look and it seems like it's Better Combat doing it from what I see reported on Simply Swords. That mod apparently does the same if you just swap two handed sword into your offhand with F - just deletes the sword. So you would need to report to them because they are deleting the items.