This can also happen when the peer leaves the channel or some error related to it.
Try to list the peers that are in the channel and see if yours is there, ``` peer channel list ```
If your channel is not listed, add again ``` peer join channel -b .block ``` here .block is you genesis block

this can happen due to the peer leaving the channel or some error related to it.
try to list the peers that are in the channel and see if yours is there
```peer channel list```
If not add again
```peer join channel -b <my-channel-name>.block```