Occasionally, the Settings / Mobile blue slider button (the one at the top which enables mobile) de-activates without any user interaction.
One time it occurred while I was using the phone. Another time it occurred 1-2 minutes after sending an SMS. Each time I reported the matter to Purism support. But they advised me, from their end, my SIMple service still appeared active.
It took me some time to figure out the blue slider had turned off. (I had only ever visited the Settings / Mobile tab one time, after installing PureOS.) Eventually I realized I could re-enable the blue slider. And indeed, my service resumed.
I do use the hardware button on the side to turn off the cellular modem, but this doesn’t seem to impact anything on the Mobile / Settings page. I’ve never tapped the “cellular” icon in the top menu. I’m very careful about the UI because I understand the software is fairly new.
Generally speaking, the service is working fairly well and I’m pleased.