I've read that people were having issues with BIAB 2020 and Big Sur with a bug with the lead sheet window.

I am having the same issue: click on lead sheet, opens a full screen blank page. In addition, I can not close those windows. The only way to get them to close is to quit app.

I am on OS 11.2.3, BIAB version 2019 (324). I have checked for updates, but there are none.

I think I saw that there was a patch available but not for 2019 version. Unless I didn't see it.

I also have a strange magenta bar across where the title of song is.

Hello Jonathan Levin,

At this time there is not a patch for 2019. There is, however, a patch for the 2020 version that will correct this issue, but you would need a 2020 version of the program to utilize it.

You can find a list of patches at the address below:
https://www.pgmusic.com/support_macintoshupdates.htm

If you need further assistance, please feel free to e-mail us at support@pgmusic.com and we'd be happy to assist.

So is there a patch in the works? I am not in a position to buy new software now and wouldn't now until the 2021 version.

The lead sheet just stopped working long after I upgraded to Big Sur.