Mentioned in the 5.1.2 update notes is a bug fix to position, in some situations, the popover so it is now in the current view.
Possibly related to that is an issue I’m now having with lyrics. I have two staffs with lyrics. When entering lyrics in the top staff, when moving from one page to the other the lyrics popover now moves to the top of the bottom 1/3 of the screen at my current zoom level. With other zoom levels it shows up elsewhere, but never above the top staff. Once I type in a lyric for that first note, the popover returns to being above the 1st staff. I am viewing Spreads Horizontally at 200% zoom. At 150% the popover shows up at the bottom of the top 1/3 of the screen.
Yes, it will be going wrong for any of the input methods where the popover can be advanced (fingering, lyrics, chord symbols, figured bass, etc.). We are working on a hot fix that will address this issue and the crash experienced by a number of users since yesterday, and should have it available either later today or tomorrow.
We’ve released a 5.1.21 hotfix this afternoon which should hopefully fix this bug. You should be able to find it in the Steinberg Download Assistant now.