Nothing has changed with any software apart from major OS updates.

Recently every time I generate new arrangement the chord sheet compresses then expands several times, then the cursor ends up 30 bars after the ending:-

IE, I have an arrangement with 60 bars, but when I click the >+ or press F4, the chord sheet reduces in size and looks like all the chords are bar after bar, then enlarges again, and repeats until the generation has finished, then the entry box ends up at bar 90 which isn't even used.

I have checked the 'Fake Sheet' option and everything there is fine, what could be the problem?