Steps to reproduce:
A vertical separator appears between the last pinned tab and the first normal tab. I think this is a glitch because the tab next to the last pinned tab clearly makes a natural separation with its rounded corner. Also, this only happens when switching back and forth with these two tabs. This does not happen when switching between pinned tabs more to the left, and normal tabs further to the right.
Orion, OS version; hardware type:
Version 0.99.123.1-beta (WebKit 6188.8.131.52), Macbook Pro M1 Pro.