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.

Problem solved.
I had an intermittent loss of VHF (old cable), did not impair VHF per se, but having the second AIS “connecting” ended up getting the just released IP address, blocking it.
New cable, problem solved.