New tab button disappeared and lost fixed position after reenabling

[Arctomachine]

Captchas

• [x] I have read the instructions.
• [x] I have searched existing issues and avoided creating duplicates.
• [x] I am not filing an enhancement request.
• [x] I have checked that this issue cannot be reproduced on Mozilla Firefox.
• [x] I have checked that this issue can be reproduced once I removed all my Mods and Custom CSS.

What happened?

After recent update new tab button disappeared from tabs list.

Looks like update somehow unchecked it in settings. After enabling it back it is no longer fixed at bottom of tabs list. It scrolls together with tabs and disappears when scrolling up.

Also tab list is not scrolled to end when opening new tab (via button or shortcut)

Version

1.12.8b

What platform are you seeing the problem on?

Windows - x64

What component is this issue related to?

Tabs

Relevant log output if applicable