Odd navigation problem Safari/Ventura

Since the latest Ventura beta I have a problem with the forum. The back button acts really weird.

I show the new topics:

I click on the first topic:

After clicking on the back button I’m not where I started:

My favourite variation when clicking the back button while on the forum site is that I land at a blank tab.

Is this a Safari or a forum problem?

All I can say is I use Safari all the time (albeit, on 12.5) and have never seen the bug you describe. That should rule out a forum issue.