iPhone 6S suddenly throwing up "no service" several times a day

[ramparts]

Over the weekend my iPhone 6S, running iOS 9.1 and on AT&T, started losing service, seemingly at random. This happens every hour or two now, and the only way I can get it to connect is to restart the phone. Switching Airplane Mode on and off doesn't help - the phone says "searching" then finds nothing. I've reset the network settings but it didn't help.

Any suggestions?

 

[MUWarrior10]

Over the weekend my iPhone 6S, running iOS 9.1 and on AT&T, started losing service, seemingly at random. This happens every hour or two now, and the only way I can get it to connect is to restart the phone. Switching Airplane Mode on and off doesn't help - the phone says "searching" then finds nothing. I've reset the network settings but it didn't help.

Any suggestions?

I've been having a similar issue...

 

[6thDAY]

I've actually had that happened yesterday night on my 6s+ iOS 9.1 Sim-free on T-Mobile. I also tried airplane mode several times but it did not work.

I ended doing the same reboot process and it connected. However, it's been working fine all day today.