<scratches head>
I can only assume that something isn't enabled that should be, then.
From the top, you have:
Configuration -> DVB Inputs -> TV Adapters
Make sure the tuner is enabled
Configuration -> DVB Inputs -> Networks
Make sure that Network Discovery and Idle Scan Muxes are enabled
You can also try disabling Skip initial Scan and restarting
Configuration -> DVB Inputs -> Muxes
Check the status of a few muxes - are they all stuck in PEND? If you edit one, can you force it to ACTIVE? What happens then?
Configuration -> DVB Inputs -> Mux Schedulers
Confirm that you have nothing enabled on this tab (you shouldn't have, unless you've created something as in your 'muxes cron page' comment, above).
And please grab a debug log - click the two up arrows in the bottom right of the screen, then click the little cog ("enabled debug output"). Go through some of the steps above and pastebin the results so we can see if there's a reason in there anywhere...