The pornographic content became noticeable for me at some point in the summer. It was strange, almost all in Spanish and with no clear connection to the 4ish subjects I followed on twitter with that account. That account ran its course otherwise I'd go back on and check if that is still happening.

In general I wonder what levers get connected to ad targeting. Several years ago I started to get substantial personalized ads in Spanish somewhere else (maybe youtube?) after a year it went back to English. I also had an account that had a 50-50 mix of German and English for a while.