Glad to hear that your problem was resolved with this change. While I understand that the Mac cannot remain in that location, the good news is we have confirmed where the behavior is rooting from so we can focus in on that area.
Per our networking guide, we recommend the following for switches:
If your switch has a “flow control” setting, please make sure that it is enabled. Also, make sure that the switch is not performing any sort of throttling that might impact communication between cores, storage, remotes, and/or audio endpoints. Finally, ensure that the switch is configured to pass multicast and broadcast traffic.
Based on your report and the results of the last troubleshooting test, it would appear that there is something going on with the switch that is causing the behavior you’re seeing. I would start by looking into the settings of your switch, making note of the settings mentioned in our guide, and try to configure the switch’s settings to improve performance.