I use two controllers. Keylab essential 88 and 61. Expanded photo to follow
The top picture is the backup laptop
The last picture is the midi assignment list on the backup laptop, and the list is identical to the main laptop. It would seem that everything should just line up but none of it does.
The widget mapping is all correct too
From this picture, the problem is blatantly obvious!
Here’s the name of the port from your first picture
And here’s the name of port from your second picture.
The port names are different. (the second one has the addition text " MIDI" at the end)
That is exactly why the second one is not working.
Among other things, the Rig Manager is designed explicitly to address this issue.
Dammit! I hadn’t noticed that. So can I correct that in the right manager for the backup laptop or do I need to do it in the main laptop and then export/import?
Rig, not right
Partly solved. I just asked the right manager to learn the new devices and hey presto! The only problem is none of the widget/fader data is there. Hopefully the all options setting will sort that
You have to add your widgets to Rig Manager as well
Now you see why we asked for screenshots 
Thank you very much for your help. It’s very much appreciated.
This (4-minute) video is worth watching (if you haven’t watched it yet (and sometimes even to watch more than once!): https://www.youtube.com/watch?v=wPtsxeVEfy0
I literally watched that earlier this evening and it suddenly all made sense. Gig performer had superb resources and I’m grateful for your help too. Thanks very much for your input.