Turning off auto placement globally remove leading space in measures
To reproduce the problem using nightly build OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 126.96.36.19939, revision: 68c5161
Load a score
Turn off auto place globally (note that you must define a shortcut to be able to do this)
save the score
reload the score
All leading space in all measures is removed. Clefs, key signatures and time signatures end up nearly stack on top of each other. Notes at the beginning of measures have almost no space after the bar lines and all items to the left of the notes straddle the bar lines.