Sixteenth notes went silent (or almost but not quite completely)

My 1/16th notes have recently become “ghost” notes all of a sudden. They may as well not be there. I think 1/16th notes are as much as a note duration can be split (I can’t make 1/32nd notes), but they used to play and now they don’t.

What can I do? Reboot?

Yeah, reboot. Sorry.