CloudWatch CPUUsage does not match top

Since Aug. 1st CloudWatch reports a higher CPU usage as normal of one of our servers (T3.mocro). I have checked the server and there is no special process running. Even when I stop all custom services and only run the linux Ubuntu 20 system, the CPUCreditBalance is getting lower and lower. Linux reports me a CPU usage of about 1.2% while CloudWatch reports a usage of more than 5%. I have stopped and started the instance, but except that I lost some additional CPUCredits (the first time about 80 and the second time again 140) nothing changed. This is how CloudWatch looks like You can see the 2 stops and starts of the instance and the startpoint off the higher CPU usage reproted by CloudWatch. We have an other server with the same configuration running without any problems. Both servers are an instance of T3.micro. Any change to get out why CloudWatch messure a higher CPU utilization than I can see on the Linux level to find out, what is causing this problem. Thanks Andi