Dear Alkrojen,
Glad to hear that you have solve the issue. For this phenomenon, i think you can ask the SIM card supplier or the operator. As you know that the module M95 just can support 2G, but the SIM card can support both 4G,3G and 2G, so when you force it to register on 2G network on your phone, it can save the registration information(priori frequency) to the SIM card profile, when you insert it to module again, it will search priori frequency with highest priority, so it can register on 2G network easily. For M95 module, it have no command can fix it, the only way that you can do is waiting for longer time when you use the SIM card in the first time. Then next time it will register on network fast. Thanks!