I think i resolved the issue… It was related to my use of Pi-hole.
I was using OpenDNS and according to logs in my router some connections were timed out or was unreachable. I changed it first to Google DNS and later to my ISPs DNS-severs. And, behold, no error in my pm2-logs (at least not at the moment) and the modules are up and running

So, you were all on to something; @KirAsh4, @McSorley and @kckndrgn!