Hi Andrew,
Thanks for your mail.
It made me go into 'debug' mode dumping the LINDA2.LOG (which I should have done before reporting my problem) and there was an error related to a missing CONFIG_HID.LUA in the MSFS Default Aircrafts folder.
Once corrected I can now make switch bindings for the FNX A320 work. I have to try with the FBW A320 as well, but I guess the missing file was the root cause, so it will work here as well. If not I'll be back 😁.
Again thanks for the hint.
rgds
Søren