My primary use case for Dex would be connected to an external monitor. My question is would Dex in that scenario work better with an S22 or a tablet which one will give me better performance.  

Kind of hard to explain but if i type a word that contains 2 of the same letter in a row it does not register the 2nd letter, I have tried 3 different keyboards and without dex so I think it is an external keyboard software issue. using Galaxy s10 on...