There may be some problem with chassis-control daemon response, you can view chassisd and messages log files to sort out the issue by using the commands
file show /var/log/chassisd
file show /var/log/messages
Log files entries can be further interpreted by using the command help syslog ------------------------(error code) that you found in log files.
You may try to give restart to chassis-control daemon by issuing command restart chassis-control
You may try Junos upgrade on the device that may also resolve the issue
Please mark this as accepted solution if it works for you
A Kudos is a good way of appreciation
Kashif Nawaz
JNCIP-Sec, JNCIS-Sec,JNCIS-Ent,JNCIA-Junos