Something similar happened to me.
Go to the "files" tab in the edit page. If the file shown is not green the file needs to be corrected. On the right is file icon click it then go to the top, select 'files just after com,zubersoft... and select the correct PDF [the base the song came from], click on it to select then ok. You should now have two titles listed, one shows the page range [the old one] of the song and the other shows the range of the base PDF. Be sure to have the correct pages then select the green listing [base PDF[. Enter the correct page range, X the old file and select ok at the top. I think that should get you to where you can edit stuff.
I think I got it all.
Go to the "files" tab in the edit page. If the file shown is not green the file needs to be corrected. On the right is file icon click it then go to the top, select 'files just after com,zubersoft... and select the correct PDF [the base the song came from], click on it to select then ok. You should now have two titles listed, one shows the page range [the old one] of the song and the other shows the range of the base PDF. Be sure to have the correct pages then select the green listing [base PDF[. Enter the correct page range, X the old file and select ok at the top. I think that should get you to where you can edit stuff.
I think I got it all.
Dell Latitude 13.5" 2-in-1 Ubuntu/Win 11
Samsung Note Pro SM-P900 12.2 Android 5.0.2
Samsung S7+, Android 12
Samsung Note Pro SM-P900 12.2 Android 5.0.2
Samsung S7+, Android 12