Presumably mobile data is working otherwise?

Do you have any restrictions on background data usage, e.g. have "data saver" mode turned on? Just thinking that anything that might restrict apps from connecting to their servers when using mobile data.

 

Yeah, it does appear to be a matter where it needs to be confirmed that your phone is actually connected to a working WiFi signal. Is this happening with all WiFi networks or just one in particular? (... the former indicating an issue with your phone, the latter indicating an issue with local network you're trying to use)

 

Oh, yeah. That's harder to explain!

If this problem is with a particular network it could be that either they have a technical problem or their firewall is blocking some sites, or blocking incoming connections from those sites. Can you access those sites at all when on the WiFi network(s) where you have problems?

 

That's strange, man...