My XZ Premium phone has an annoying issue. Whenever I allow the phone to use the internet with 4G connection, it keeps losing or resetting the connection completely, to where I also can't make phonecalls. It'll have a working phone and internet connection for a few seconds to a minute or so, then it disappears completely and it reconnects after a bit. This happens over and over.
This doesn't happen when allowing only 3G to be used, and the provider's area coverage is great for both 3G and 4G, so that isn't the issue either (it happens wherever I am). Same provider doesn't have this issue on my partner's iphone, and I had a new SIM sent to make sure that wasn't the issue either.
Is my phone's antenna screwed? Any other possible causes? I've had this phone for 2 years now, but aside from the 4G issue it is still in really good condition.
It says it has the latest system updates installed, and is using android version 9.
