breath marks are not shown

Windows 7, 2a72911

Open a score that containy breaths marks, for example breath-1.mscz from the vtests (attached, for convenience):
breaths are not shown in the score, but you can see them in the navigator

Add breath marks (which are visible now), save, close, reopen:
same issue, not shown in score, but visible in navigator

Create a new score from scratch, add breath marks (which are visible now), save, close, reopen:
same issue, not shown in score, but visible in Navigator

Detected while working on #108616: Add Tick Mark to Breath Marks in palette