Galaxy S23 

I bought a brand new Samsung Galaxy s23 ultra a month ago and I've been experiencing a huge problem with my mobile data recently. i suppose the latest update caused it but it can be anything else although ive ran out of possible ideas what it can be. so basically when I have a 4g/3g/2g toggled on it keeps saying no sim no service for about 5 seconds and then it back connects to 4g/4g+ but it won't go automatically to 3g/2g so it turns off my sim and mobile data completely for a few seconds. ive already figured that if i turn on 3g/2g mode it works absolutely fine but it's a way slower connection and I need my 4g working. I've already tried turning my phone off, restarting it, resetting mobile network settings, changing sim etc.