SSM is working but after a few minute, SSM is not working. and When I stop and start the instance, SSM is working. but after a few minute, SSM is not working.

SSM is working but after a few minute, SSM is not working. and When I stop and start the instance, SSM is working. but after a few minute, SSM is not working. SSM Log is as follows. mdsinteractor stopped temporarily due to internal failure. no EC2 instance role found. Instance Low Spec Problem(CPU Usage 60~70%, Disk is 20%)? or SSM Agent Problem?