I’ve been engraving some art songs lately, and I’ve noticed that pedal lines tend to disappear when other elements are edited. For example, in the screencap I attached, the pedal markings were fully entered, but when I added the 8va line, the pedal lines disappeared from that system onward.
I noticed the same issue in the song before this one, as well. If I selected the beginning of the line and moved it forward and back into place, the lines came back, but disappeared again when I made more changes to other elements of the score.
They remain invisible in Print Mode, as well.