Apple id

Have two device that use same id has to sign out of one and then when signed back in the line that was on that device wasn’t working but the line number for the device I have was in the iMessage feature on the other device and the right line had a small circle spinning constantly and I could send a msg from my device to the other one but it come right back to my device like it came from the other one??? I did read something somewhere when I was looking through it trying to figure it out that it said if you removed that number, it would be removed from all of the devices signed in with that app Apple ID something about contact carrier to fix it just wondered if anybody’s have experience this problem