Dashcam mini protect video, press down button, press how long?

[fieldofview]

Question about the Dashcam Mini 0805, to protect a video from being overwritten, how long to press the down button? I came across a scene I wanted to protect the 5 minute video from being overwritten, I pressed the down button momentarily. But on reviewing my files, don't have that scene. I recall previously that the camera would create a new folder to store files from being overwritten. On reviewing what was on my SD card, there was no separate folder for saved video. Thanks