As your phone makes calls while at work this leads to that the phone and sim card are working as they should be @Trude63
So instead this could be a network issue in your area or possibly mast congestion where lot's of people are using the masts at any one time.
Most mobile networks have a mast Checker where you can see via your postcode / zip code if there are any known issues with your local and surrounding masts.
These can be found in your network app or on your networks support page's.
Unfortunately mast congestion does not usually show on these.
Your Network's Customer Services can check your hone area too if you contact them.
When at home try resetting your network connection in the phone's settings to see if this helps at all.
I wish you all the best with this.
Daily Driver > Samsung Galaxy s²⁴ Ultra 512Gb ~ Titanium Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
