My ST300 appears to have updated 6th/7th Oct and now seems to be turning off when there’s no signal from my Set Top Box via the HDMI Cable. It needs (ST300) turning back on again via the remote.
Ive taken all the cables out, put back in and powered it all off and on again
To make sure I am running the latest version(s), I've just downloaded the latest Mac (10.12.6) App from the Bose Support site and its version 15.120.23 (https://downloads.bose.com/ced/soundtouch/soundtouch_controller_app/index.html)
ST 300 is saying the latest is 15.0.20
I dont have the option to turn off power saving, but it does look like a potential fix. As 20mins seems about the right time to turn off.