Joying Dash Cam stopped recording years ago?
I have a DE-JY-UM135N2D head unit and the Joying USB dash cam connected to it.
I wanted to search for a recording of a thing that happened last week while driving, but it seems the most recent recordings are from 4 years back!?
I can replay these old recordings using the camera app, so the card is recognized fine (is a genuine quality brand card)

When I try to start a manual recording it stops after two seconds, and no new video file is added to the sd card
(the camera footage is shown on screen, so no problems there)

When I choose to format the card, the system says after a second that the card is formatted succesfully, but still all the old recordings remain on the card.
Obviously nothing happened..

What could be the problem?
Problem seems solved!
Seems that the expensive A brand SD card was broken. Of the 32GB, there was only 19GB data on it when it stopped working.. So the card was not even written full once.
Other (no name brand) card is in the unit now and still working fine. I'll keep an eye on it.
Periodically switch to the camera app to see what date the last recording was made, so you can step in quickly when there is a problem.

Shame that the Joying unit / camera app does not give an error to warn you