Not registered on network
I am currently overseas and hold 2 SIM cards. Earlier I had no problems with receiving and sending text messages (SMS) with my starhub SIM but have been unable to do so for a few weeks now. I tried making a call today with the starhub SIM and was greeted with a 'not registered on network' error message. Receiving OTPs is an important function and the only reason I'm still holding on to the Starhub contract. Would appreciate assistance on this issue pls. I have also done a factory restart on my phone, but to no avail.