PC sleeps during stream or download

I’ve noticed that when watching movies direct from PC running running JF, or when movies etc are being downloaded or streamed, PC, which is set to go to sleep after 30 mins, goes to sleep. This does not happen with Kodi or other file transfer software when playing movies etc.
Is there a stay awake function in JF, whilst doing the above? How is JF implemented to avoid sleep timeout.
cheers,

There isn’t anything to keep it awake to my knowledge. I’m going to assume that you’re using a browser, and this browser is probably not reporting that video playback is happening to keep the OS awake.

Does this also happen with YouTube/Netflix at all?