I've not been able to find much information on this bug, apart from it having existed since Notion 3.
In Notion 6.6, on treble staff + guitar TAB, one cannot write a whammy bar effect starting at the second ledger line above the staff or higher. Attempting to do so distorts the display, pushing the TAB staff far down the page. And cutting of the audio.
Writing the same effect lower down on the staff works as it should.
A simple workaround, of course, is to write any note above this imposed cutoff on the staff 8va. This can be read by guitarists and sounds correctly. However, one would not want to annoy a pro guitarist by handing them such a printed score. Which means Notion is not yet a professional tool - even at version 6!
Other guitar effects seem fine. The problem is just with the whammy bar effects.
I don't write much code anymore, but the fix can't be that hard to find or difficult to correct.
Please fix this.
Thanks and regards