The PATH variable is only updated once at the start of the agent in 2.0. There must be a different bug in 2.0. Unfortunately there is little I can do at the moment about this. For 2.1 we were able to reproduce this issue on our own installations and debug it with strace. Without a strace log of a process that has gone bad I have no idea where to start looking. If you experience the issue again you can capture a strace log using
strace -p <PID> -f -t 2> strace.log
We set -f to also follow any forks started. Replace with the main PID of the agent. You can find the main PID using systemctl status
❯ sudo systemctl status check-mk-agent-async.service | grep PID
Main PID: 476659 (check_mk_agent)
I do not have a 2.0 agent running locally with systemd so your service name might differ.