iphone15 has a signal but no internet connected with mobile data

I got an iphone15 which often fails to connect to internet with mobile data. It works very well with wifi. Initially I thought it was a mobile provider issue so I've changed providers but all are same. I also have iphone11, so I tested both with same provider, vodafone in the same place. iphone11 connects the internet really fast whereas iphone15 fails with a time-out error. Any advice on how to fix this?