Network disconnected

Hello, i am a provider in Led digital signage and i used Novastar wich used 4G Module EG-25G. Randomly, the network disconnects. Even if i restart the product the disconnection is still present. To reconnect, i have to unplug and replug the SIM Card and it’s OK. Have you a solution please?
Thanks in advance.
Best regards.

Will this event still occur?

Yes, i have allways the problem for all my installations. After power off, if i restart, There is a good chance that I have the problem. For now, I make sure to never turn off my products.

Best regards.