Are the songs your own? you might have used custom chord qualities (not formed from the official ones the player understands—use the Quality menu or correctly use the keyboard to input the correct qualities).
Or are you playing back the exercises or the large playlist songs (Jazz 1300 etc.) which are all checked for playback and chord diagrams?
If you change to Guitar font, do the diagrams show? or do the scales?
You could post a song here that does not behave and someone can look at it.