Pinned tabs disappear when maxed out on ff 109

[listvin]

Pinned tabs disappear when tabs panel goes into "overflow" mode with scroll buttons.

Possible steps to reproduce:

1. Open new ff window
2. Go to example.com
3. Middle-click More information to open IANA's page and pin it
4. Go back to example.com tab and duplicate it 24 times (ctrl+drag tab for example)

Now I have 25 tabs of example.com and pinned IANA. I can scroll to see all 25 examples, but no pinned iana =(
Actually any amount of pins disappear, exact steps for kinda minimal representation =)
Pinned tab itself is ok ofc, just not visible. It's possible to shift+ctl+tab to it.

phroton version: 7d56b4e from 22 jan 2024
FF version: 109.0.1
OS: Linux Mint 21 (the one based on Ubuntu 22.04 but with X11 by default)
1920x1080 display

P.S. Great work overall and "packaging", love it. Thank you.

[listvin]