Trouble with Parts in Musescore 3

I'm having trouble with the parts of an arrangment I'll attach. The full score looks right to me and plays properly. The basic form of the song is:
- Intro
- Verse 1
- Verse 2
- Bridge
- Verse 3 (solo in our version)
- Bridge
- Verse 4
- Outro / Coda

Because of trouble I've had previously with D.S al Coda I chose a technique someone here helpfully introduced me to:
- Intro
- Verse through Volta 1 (repeat)
- Verse through Volta 2 / 3, including the Bridge (repeat)
- Verse through Volta 4 to end

As mentioned the full score looks right and plays correctly. (I somewhat redundantly added "simple drums" including 2 measures before the beginning as a rehearsal convenience.)

My problem:
All the parts appear broken in the following sense:
- Volta 2 / 3 should be 9 measures long with the repeat at the end of 9 measures
- in the parts the measure count is correct, but the repeat comes after 2 measures.

I tried deleting and recreating parts, but this didn't seem to help. From an old print-out I can see that at least some of the parts were once correct.

Is there a function to refresh parts? (I'm wondering whether these parts reflect something about an older structure of the score.)

Maybe someone has an idea how to get the parts to reflect the structure of the score? I'd be grateful.