Tempo markings do not clear time signatures on single-line staves

[oktophonie]

Describe the bug
Tempo markings collide with time signatures on single-line staves.

To Reproduce
Steps to reproduce the behaviour:

1. Create a score with a single-line stave (drum of some sort)
2. add a tempo marking at the start

It looks like the distance from the stave itself (i.e. the only stave line) is being honoured, but autoplace is not kicking in to avoid collision between the tempo marking and the time signature. Compare two lines:

Same distance from top stave line, which in this case happens to be enough for it to also clear the time signature.

Expected behaviour
No collisions plz.

Platform information
OS: Artix Linux, Arch.: x86_64, MuseScore version (64-bit): 4.1.0-230480309, revision: github-musescore-musescore-466c7d3