"Jump to latest" Marker appears at End of Timeline

[lunar-seal]

Describe the bug

Consistently reproducible by jumping to the end of timeline by clicking the link to an original message that has been replied to.
TLDR see video:
https://github.com/user-attachments/assets/cc4cd496-15ed-42d7-85fb-ec742ce741da

There might be other cases, I'll reopen the issue if it happens again after this has been fixed

Reproduction

No response

Expected behavior

No response

Platform and versions

Firefox/Web 3f4c1a8

Additional context

No response