I can't make voice calls on my Apple iPhone X iOS 15.1
Cause 2 of 9: There is a temporary network problem
If there's a general problem making phone calls in a certain area, it may be be due to a temporary network error.
Solution: Try making a call later or when you're in another area. Check the network status in your area for planned or unforeseen events, such as maintenance or outages which may affect your Lebara services.