D3 doesn't switch between left and right hand fingering

I have a project file containing several flows made for guitar teaching purposes. Upon 1st opening in D3, I got a message that the file was created in D2 and needs to be adjusted to D3 requirements.
There were several piano style left hand fingerings already in it that I manually had modified to make them look like guitar fingerings (placement next to the note).
I’m unable to switch between l and r hand fingering in this file. The arrow keys don’t work. LH fingerings that I add keep showing above the staff, although the entire project contains only two classical guitars plus a guitar bottom, so D3 should know that lh fingerings are supposed to show next to the notes.

Did I miss something?

Thanks a bunch in advance

Please see the ‘Projects from earlier versions’ paragraph at the end of the section on ‘Guitar fingering’ in the Dorico 3 Version History PDF.

:+1:t2:
Thank you!