I am SO sorry that the video stops abruptly...I have a new cellphone and it seems I still have to do some installations on the camera about the length of the videos! I still hope it is enjoyable for you to watch!
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app