Staff Text — Odd frame margin behavior
Observed in MS 3.5.2 and 3.6
There's been no reply citing a remedy for this post, so I assume the frame margin issue may be a bug.
And for what it's worth, in the Inspector, I think Border would a better name than Frame for this property. Particularly because MuseScore has a number of types of frame. And because the settings affect what is normally considered a border.
And please note that the attached score is more recent that the one attached to the referenced topic.