LG G4 Slo-Mo editing not working anymore.

[AC Question]

I can't for the life of me figure out why I can no longer record a video with slo-mo setting on my LG G4 and then edit just the slow motion part later with little sliders to select only the portion you want to play in slo mo. I believe i was using google photos to playback and edit before but I've tried everything including a factory reset. It works playing with default app but the whole video is slo mo which is useless! Thanks in advance for any help.