Stave space size awkward to edit
The stave space size in Page Settings is awkward to edit. As soon as one deletes a digit it is replaced with a zero. To see the effect put the cursor at the right-hand end of the number then press backspace. The entire field cannot be replaced if highlighted and a new value typed. The only way seems to be to inset the cursor at the right-hand end, backspace to convert the least significant digits to zeros, insert again at the right-hand end, backspace to remove the zeros, then type the required value. That's a very awkward manoeuvre.
Same comments apply to delete, unless then entire value of the stave space is highlighted.
Same comments apply to scaling in pages settings.
See discussion thread: https://musescore.org/en/comment/927892#comment-927892
Comments
As for as know, it's a known (and annoying I agree) issue: #280363: [EPIC] Page Settings: fixes and changes
In particular: #281445: Page Settings: staff space (spatium) control pads input before user has finished editing