Just for information I upgraded my MXQ OTT HD18Q to 7.0.2.3 (from 7.0.2.2) and my DVB usb card is not recognized anymore (no device displayed in http://X.X.X:9981 tvheadend web server)
I was obliged to downgrade to 7.0.2.2.
My DVB USB card is a RTL2832U + R820T Tuner.
I use it to watch TV since Openelec firmware version 6.0.0.2 and I've upgraded firmware many times before with no issue.
Please post a log with working/non-working tuner. Collect the log right after booting, no other activity is needed.
Also K's letest builds for the S805 are the best so far except for the first 10secs or so of some files skipping which I had never experienced before, apparently no one else suffers from this even people with the same board. And for the record sometimes I can't even get the skip function to play the first 10secs! Just annoying but I can live with it. May try a clean install and try it without installing my backup i.e No addons. Tried this before in the past but it didn't make any difference.
You're not the only one! Can you tell since which build the 10sec bug started to happen? Is it 7.0.2.1 and it was OK with 7.0.1.4?