CTRL+ UP / Down do not work with an external keyboard

I use an external bluetooth keyboard with my android fold phone and it works perfectly.
Only exception is the combination of CTRL+UP / Down (essential in Checkvist!!).
Anyone else having this same problem?, Any suggestions on how to fix it ?
Thanks

I’m not sure if this will help, but I had a similar problem with keyboard commands on a bluetooth keyboard. Mine was a Arteck Universal. I think my issue was a function key combo that was giving me problems, but I contacted the manufacturer about the problem. They gave me a function key command that successfully changed the behavior of the keyboard.