Changing instruments on single staff leading to problems.
I arrange opera orchestra music which often has Horn and/or Trumpet in F, Eb, E , D. C etc . When I change the instrument on a staff sometimes it stays and sometimes on the next page it reverts back to the original instrument and frequently puts in extra sharps or flats (see measure 631 in the enclosed file.). For this file I went through it several times and made sure that all the "Change to..." were to the right instrument but if I close it and reopen it or click on "Concert Pitch" and then return , the instrument changes.
For example in Measure 497, third staff , I changed all the horns to Horn in C but on the next page it list horn in Eb for 2nd staff, and Horn in Ab for third and fourth horn and then in measure 631 There are mutiple extra #'s .
Although I indicated that it reproducibility is random , it happens very frequently and takes a immence amount of time to do a workaround.