I'm struggling an issue since a couple of month.
I'am using kstars and ekos since almost two years now.
But this summer I started to find that my astronights sessions failed beacuse of eqmod disconnection while I was away
Sometimes it works, for hours, for night, sometimes it disconnect several time in the night.
When a disconnection occurs I cannot reconnect eqmodmount from Ekos, I must go to my observatory and physicaly switch the USB port on the computer, then in ekos I have to scan port and affect the new com adress (com0->com1->Com2...)
I first thought it was a cable issue but with a new one nothing change.
Is the adapter plugged into a usb hub? Powered or otherwise? If so, I do not recommend that. The adapters work best connected directly to the system. Just my experience using a Raspberry Pi.