I am not sure about RM9, but it may be this issue:
[rzamor1]
Ctrl+Shift+(Left or Right) will rotate through the History List. The RM Edit Person screens are non-modal so commands for the main program can still be accessed
reported here: https://community.rootsmagic.com/t/marking-words-with-ctr-shift/11611
It seems this is new RM8-10 … nott that I like it, and it is most irritating as I use “Ctrl+Shift+(Left or Right)” almost automatically …