Hello @Ants,
Thanks for contacting support with the extensive description of your network and I appreciate that you have started trying to troubleshoot the issue, your feedback is very appreciated. I also believe that this is a networking issue that you are facing. You mentioned that all of the devices are connected to the Cisco Catalyst switch. We have had reports that enabling flow control helped users with similar symptoms that you are describing. More information can be found in this thread here:
I would take a look to see if you have similar options in your switch and try to enable it. As for the Logs, I have enabled diagnostics mode on your account and the next time that your Core is active, our servers will receive said logs and I will submit them to our QA team to see if they can provide an explanation to what exactly the error Ropieee is generating. We will be in touch after we have received those logs on our end.
Thanks,
Noris