Android box upnp sleep problem?

Im using my M8S box as the main UPNP server in one room and set everything up fine. When I put the box into standby with the remote I can still access the files fine for a while but then all the devices I have that can access it just stop seeing the main box. Is this because of Android going to sleep in the background or something in Kodi itself? It seems to be ok seeing the box in standby. Does anyone know a way for it to see the box all the time? Any help is much appreciated.

Sent from my SM-N920P (typie typie)