It could be a number of things, none I think are GOS related.
Is your plan 5G enabled? years ago when 5G first hit the UK, my mum got a new plan, it had 5G, mine didn't I had to get them to enable it for me, they also have to send me a new SIM.
Honestly, unless your doing massive downloads or streaming 4k content, 5G isn't noticeable I turn it off mostly