We did the same as you said but still the bug not fixed. I changed my mobile network and again I purchased a new SIM and recharged my account even having a active plan but the problem not solved. I checked with your Samsung customer service they run ...
I am also facing same problem in M31. first I change my network from Airtel to jio but problem not solved after that I bought duplicate sim and then I recharge even I have a valid pack. after that I went to Samsung service center and installed softwa...