Jumpy "jump to latest message" overlay

What happened?

The "jump to latest message" appears to respond to some width that's affected by the scrollbar's visibility. Would be less distracting to keep it centered at all times.

Steps to reproduce

https://github.com/user-attachments/assets/17c7d235-b591-4392-a3c2-487090dddabb

Expected behavior

Having the message centered at all times.

Version

v0.85.0