I had the same issue with my S9 and never resolved it: if I spend a few hours in a no signal area, I then can't make calls, send/receive texts, or connect to data when signal comes back because it says I'm not registered on the network and emergency calls only. Restarting the phone always seems to resolve it but I can't understand why it is doing it in the first place and it's frustrating as, if I don't notice, I miss any incoming calls. It's only if I'm somewhere with no signal for a while, it doesn't tend to do it otherwise. Any ideas on a fix? The software is up to date.
Thanks for the reply, it is the best network for where I live but unfortunately there doesn't seem to be any good network for where my mum lives! It only happens when I'm visiting her and if I spend too long in a particular blackspot at work, but it's so annoying 😕
Unfortunately @Jmiauhu even in this day and age all Network's have fringe coverage area's and not spots so customer's can suffer from signal loss.
If your Mum has Home Broadband Wi-Fi and you have access to Calling over Wi-Fi with your Network provider then thus could be an interim solution to keep connected or if your phone is a Hybrid Dual Sim phone then use another Network's sim card in it i.e a Pay As You Go type and switch to the alternative to try and keep connected.
Current Phone >Samsung Z Fold³ 5G.
Previous Phone > Note 20 Ultra 5G SM-N9860.
I'll pass on a possible suggestion which may not have any bearing in this issue.
I had a problem here in the Netherlands with a specific app for a supermarket. Sometimes the specific app would tell me I'm not connected to the network though I clearly had a strong signal.
I would restart my phone, and that would always solve the issue.
I had the idea of instead of restarting the phone, I would Force Stop the specific app in Apps. I would then open the app in question and everything was good.
Would Force Stopping 'Phone' in Apps, and then clicking on Phone again, save you from restarting the phone?
Just a thought.
That solved this issue and more importantly, cost me considerably less time.