The WiFi on my Galaxy S24 Ultra doesn't work properly on a per-app basis.

For example, while I can browse Twitter from the Chrome app, I can't use the Twitter app at all most days on my WLAN unless I switch to data over LTE. Spotify and Telegram have the same issue. The reception icon on my phone is full and the issue even occurs when the phone is right next to my access point. There is just almost no data going through. In the Twitter app, the posts and texts seem to load fine, but images and videos don't load at all or take minutes to load. Spotify sometimes shows the "no internet connection" warning even though I have perfect WLAN reception and Chrome is working fine too at the same time. If I leave an affected app open in the foreground for tens of minutes it sometimes starts working normally again.

My old S21 Ultra and my desktop PC have no connection issues at all.

I don't see a single indication that this is NOT a Samsung issue. If it was an issue with my environment, other devices like the S21 should be affected. If it was an issue with a specific app, it shouldn't be affecting so many apps. If it was a routing issue, then obviously the affected apps should have the same issues on multiple phones.

I'm convinced that this is on Samsung to fix. Not having properly working internet access on a smart phone is hugely frustrating.

Edit: I just found the superfluous "Intelligent WiFi" options and turned them all off. Especially "Prioritize real time data" just sounds like the perfect snake oil feature that would cause such grief. Seems to have fixed it for now but I won't know for sure until testing it for a few days.

Edit2: Changing the "Intelligent WiFi" settings didn't help.