Cutaway courtesy clefs in 3.6 nightly don't show before time signatures

There seems to be a new problem with the functionality introduced in https://github.com/musescore/MuseScore/pull/6461.
When switching on "cutaway" in the staff properties, a courtesy clef that has been added to a measure shows up most of the time as expected. However, when there is a time signature present, the courtesy clef is no longer visible.

In the attached score, this is what it looks like when cutaway is disabled:

This is what it looks like with cutaway enabled:

Measure 3 and 6 works as expected, but measure 4 does not. And, neither does measure 5; I've noticed that if there WAS a time signature in the measure but it was deleted, the courtesy clef is still prevented from appearing (this is fixed on a restart of MuseScore though, so it will probably show up correctly when downloading the file. To reproduce it, simply add a 3/4 signature in measure 5 and then delete it. The clef won't appear).

OS: macOS 10.15, Arch.: x86_64, MuseScore version (64-bit): 3.6.0.450053582, revision: 0bf33e1