I see what you mean. I saw the same issue on my own model a while back while I was working on the blend modes, but then I fixed it within RahiTuber itself.
This is what confuses me - I'm using Krita for my art too, and i have multiple models which use the linear scale filter, and i don't see this issue arise on my own computer.
Please can you contact me on discord (@rahisaurus) and send me your layer set so that i can test it myself?
Hopefully if i can also see the issue then i have something to work from.