My phone just started to display the message that says "SIM 1 not allowed" from nowhere. I have been using the device for over a year now and never had that problem. I thought the problem was my SIM card, so I put it in slot 2, and it works just fine. I bought a new SIM from a different carrier, and the message comes up again. I swapped the SIM cards but still the SIM 1 not allowed still remains. I have done restarting the device among other things. Why is my SIM 1 blocked. It's obviously a software issue to block my SIM not a hardware one. I bought the phone for the convenience to use 2 sim cards, but now when my SIM slot is blocked for no reason and without any explanation of how to troubleshoot, it's very disappointing.
Hey there, if you are using telkom. You are not alone, I'm using the s21 5G dual Sim but for the past few days I have also received that notification Sim 1 not allowed. I'm not sure why but I'm stuck on H+ network on telkom. Cell c is 4G+... it has something to do with SA network providers over this weekend your phone should be okay.
My SIM 1 got blocked when I was using MTN. I tried Vodacom but the SIM 1 still continues to be blocked. In other forums, people are saying it's these network providers that block our IMEI. What's I don't understand is why they block our phones because we are not on contract. To me this seems like scammy business practices. Makes no sense to buy a phone for 2 sim cards and one gets blocked from nowhere with no reason.
The device does not have any hardware issue. This is a software lock. A look online shows you that this is quite a common problem. On all those occasions in the Samsung communities, it was a software lock. I am away from a service centre and I can't visit them early, but I need my phone to work. I suppose this issue should have a fix because it's a known problem. It's disappointing that on all community questions, the moderators don't provide a solution except to say visit the service centre.
Hi all, I am having the same issue since yesterday the 17 of September: SIM 1 not allowed with Vodacom. Also slot 2 does not read the SIM. I tried the SIM card in another phone and it works. I have installed September software update few days ago.
