I'm facing a similar issue to this one, How do I disable suspend mode?, except I have a Raspberry Pi 3 and am running OpenELEC 6.0.3. When I leave it on without using it for awhile, I can no longer ssh to it or connect to it via samba. I have to use it use again and then I'm able to connect to it (although occasionally I have to reboot in order to be able to ssh to it for some reason).
Is the wifi going into sleep mode when there is no traffic? How can I disable it on the Pi 3?