New here. Greetings everyone!
So, there is no better way to start in a forum that with a question.
Trying to insert a figured bass, it should be a “3” under the note, however Dorico does something different:
How can I write it correctly?
Welcome to the forum, Toto23!
There is an option to show the 5/3 figures in Engraving Options > Figured Bass.
But the reason they are hidden by default is that 5/3 is assumed when the bass note changes. Similarly with the 3 of a 6/3, the 6 of a 6/4/2, and others. Dorico does the “correct” (standard) thing by default.
That was fast!
I thought it had to do with the different kinds of notation for the figured bass.
Thanks a lot, it worked. 
There’s a useful video on figured bass in Dorico 4 here…
Thanks, very helpful.