Fitting different durations in figured bass

In the handbook (https://musescore.org/en/handbook/4/figured-bass) it says that you can fit more than one figure under a single note (in my case in the second beat of a dotted minim) by pressing Ctrl+5.

I've tried this, and it doesn't work (pressing Ctrl+5 just enters '5' straight after the first figure at beat 1). Am I missing something?