Steps to replicate the issue (include links if applicable):

• Create a wiki page with multiple identical section headings
• Edit one of the latter sections
• Submit the edit

What happens?:
You'll be redirected to a wrong page ID, e.g. #Title instead of #Title_5.

What should have happened instead?:
It's self-explanatory.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):
1.45.1

Other information (browser name/version, screenshots, etc.):
Firefox 148.0