Hi,
I configured a HAT with PPP tutorial and auto-connect service, and it successfully worked for a couple of weeks. However, today the HAT did not connect to the internet. Service is active and I don’t think there is a configuration problem, as it previously worked and still works in other raspberry Pis with the same SIM card provider.
How can I discard any hardware problems?
I attach image of the Raspberry with the 4G module:
