Not registered on network error

I have a Samsung Galaxy Note 9, and from time to time I get a "Not registered on network" error when I go to call someone.

Every now and again I realise that things have been very, very quiet on the phone front, and realise that my phone has been in this mode for one or more days, and I haven't noticed. Everything shows as normal, including the level of cell reception on the network. When we use wifi extensively, this 'normal' appearance of the phone makes it very easy to miss the problem of being off the network.

There are a number of fixes that others suggest, however, I have found a three step process tends to work well for me (and it is usually the last step alone that makes the difference), as follows:

1. Shut the phone off. Restart.
2. Go into settings, almost scroll right down to the bottom, and check the software is on the most up to date version. If not, update, and restart.
3. Put the phone into flight mode. Wait a couple of minutes, then turn flight mode off. The phone should now be on the network, so try calling someone.

I have no idea why Samsung phones do this (as my old Note 4 used to do this as well), but going in and out of flight mode seems to make it reconnect with the outside world.

Long may it continue to work!


Sam