I don’t know if this is normal or not. About 1 or 2 times an hour the unsolicited message that +CREG status is 0 (disabled registration) or 4 (unknown) and automatically reconnects. Sometimes it takes several seconds to reconnect. I had set CREG=2. That reports the same cell tower is connected to each time. Identifying <lac> and <ci> below are replaced with x’s. The output below is from about 2 hours duration.

+CREG: 0

+CREG: 2

+CREG: 5,“xxxx”,“xxxxxxxx”,7

+CREG: 4

+CREG: 5,“xxxx”,“xxxxxxxx”,7

+CREG: 4

+CREG: 5,“xxxx”,“xxxxxxxx”,7

+CREG: 4

+CREG: 5,“xxxx”,“xxxxxxxx”,7

+CREG: 4

+CREG: 5,“xxxx”,“xxxxxxxx”,7

+CREG: 0

+CREG: 2

+CREG: 2

+CREG: 0

+CREG: 2

+CREG: 5,“xxxx”,“xxxxxxxx”,7