usbserial error - resource busy / could not find a PTY

Hello

I have a completely new MacBook Pro (late 2019), delivered with Catalina 10.15.1. In my line of work I need to be able to access network equipment through console and have a usb-to-serial cable (both usb and usb-c versions). In previous MacOS these work without any drivers (not the usb-to-serial hardware model with need for PL drivers)

But when I try to execute

screen /dev/cu.usbserial-A9SC3G27

I just get the error

Cannot open line /dev/cu.usbserial for R/W: Resource busy
Sorry, could not find a PTY.

If I look into the system.log this entry is logged every time I insert the cable

xpcproxy[884]: libcoreservices: _dirhelper_userdir: 557: bootstrap_look_up returned (ipc/send) invalid destination port

I have tried to see if any other resource is using the ports, but haven't found anything (e.g. a modem or such), but I am open for suggestions.

I have also tried

• reset SMC
• safe mode (not possible to access usbserial when in safe mode)
• tried through another test-admin account
• I have tried to see about running services (ps -ef | grep usb|serial|console|etc) - open for suggestions
• other usb(-c) devices are working in the MacBook (e.g. an Apple screen, a non-Apple screen through HDMI, usb sticks etc), so I guess the hardware ports are working as they should
• I know the usb cable is good since it is working on a Mojave Mac.
• haven't found any solutions online. I did notice a lot of "Arduino guys" are complaining about communication problems with their Arduino devices through serial. They have fixed by updating/reinstalling their drivers, but I am not sure if that would help me since in my case it isn't Arduino related!?
• no running screen sessions (screen -ls)

So I would very much appreciate any suggestions as to what could be the issue and how to fix it. I would guess it has something to do with Catalina, maybe a bug or driver issue.

I hope that someone is able to help me since I really need this work related.

Thank you in advance.