Running CE concurently on two different computers?

I have been doing this for 10 years now: one laptop running current (windows 10) to plan/plot/massages my next day routes, and transfer them to my 10" tablet running Win 8 for the actual sail the next day voyage.

My tablet died and I couldn’t find anything similar. Got a Widows10 Lenovo notebook and built it to the same setup as the defunct tablet.

This seem to work fine, until I tried them together.
I could not get the latter to connect to AIS no matter what I tried.
Next day I started on the notebook again and it worked just fine. But the Laptop couldn’t connect to AIS now. AIS only talks to one OR the other, how can that be?
I have not upgraded anything in my VesperMarine AIS Transponder software/firmware.

Is CE preventing this???

No, CE doesn’t prevent this. This sounds like a limitation of the Vesper, or some other behavior they may know how to workaround. Give them a call since they’d be the ones to most likely understand the behavior.

My limited experience is that laptops will not share inputs either between laptops or programs on laptops. I often run CE and OpenCPN on a laptop but only one will have the USB GPS input. To get both programs fully functional, I need to run two USB GPS and direct each program to a separate COM port. Similarly when I have two laptops running separate programs, each needs its own USB GPS. It is likely the super tech savvy have a work around but that is where my bumbling inadequate tech skills have taken me.

The VesperMarine AIS “modem” can accept up to five IP address/ports connections concurrently. Has been running fine for 10+ years now.
Working with their support.
Will report when fixed.