@The_Elf
please try this:
create a new miditrack and map the input to your remote control device.
this little trick helped me to keep all my midi remote controls in proper connection.
somehow this midi track ensures the connection stays valid.
Cubase 13.0.40 did not solve the issue for me neither, as soon as i remove those midi track, my midi remote controls will become disfunctional as soon as i add or remove any midi device.
full thread on my issue:
i´m keeping my fingers crossed that the small workaround will also work well for you!