This is what I usually do

Check your video playback settings in the settings menu. Maybe something got messed with.

As strange as it sounds check your hdd storage space too. Blu-rays save some info locally for playback purposes and bd live content etc. if you're maxed out it may mess with that.

idk i dont use my ps4 for that my ps3 is pretty much my blueray/dvd

i know for anything on usb n shit u need o use the media player maybe you do for dvds n shit idk

If anything purchase the accidental warrenty in ps store then use it.