Trouble with figured bass

How do I get the 3 positioned correctly in the 5/4-3 suspension in the last measure on the first system? If I place the cursor after the 4 and press Ctrl+5 to advance to the next crotchet, the cursor moves to the top row. I must be missing something very basic here.
Same thing goes with the accidental in the 4-3 suspension in the last measure.

Thanks!

Generalbas_övning 24 (fixed).mscz