SSL error has occurred

I am new to Home Assistent but I have it up and running but now I have a problem with the iPhone app. When I am away from my wifi (and therefore on 5G) I get this error:
“An SSL error has occurred and a secure connection to the server cannot be made.
NSURLErrorDomain -1200”.
I am using NabuCase cloud and I have paid for the next year.
It has been working but has stopped working.
Any help is welcomed.

BR
Peter

Check your internal and external url in the server settings on your companion app.

The error was solved by rebooting my HA.

BR
Peter