"Automatic bracketing" feature keeps overriding custom bracketing when hiding/unhiding staves
Steps to reproduce:
1. Create a score with 2 violins, 1 piano, 1 cello.
2. Manually delete the light square bracket that connects the two violin staves.
3. Press "I" and uncheck the "visible" checkbox next to the Cello part in the Instruments panel. Press OK.
4. Now the light bracket you deleted in step one is back.
5. Delete the light bracket again.
6. Press "I" and check the "visible" checkbox, press OK.
7. Now the light bracket is back again.
Repeat steps 2 to 7 any times, the result will be the same: the bracket keeps coming back, no matter how many times you delete it.