Everything you've indicated up to this point indicates that the tv firmware is confirmed.
It should not be possible for you to make a setting change to the tv which would cause this type of prohibited operation or problem.
These hisense tvs are some of the lowest quality tvs made, and have very high failure rates, so problems like this are common, even for a tv that is only a year old.
There is one further step you can take here, both as a possible fix, as well as a diagnostic evaluation:
1) Unplug the power cord from the outlet
2) Wait at least 1 hour (60+ Minutes)
3) Press and hold the power button (on the set, not the remote) for 60 seconds
4) Keep holding power button while plugging back in, and for another 60 seconds after. When plugging back in, go directly to the wall outlet, bypassing any power strips or surge protectors.
If this reset process does not work, it would unfortunately confirm an internal hardware failure.
At that point your next step would be to call hisense to attempt to file a warranty claim. If they won't cover it, which they may not based on age, then it would not be worth fixing. It would cost twice as much to repair as it would to buy a brand new tv with a fresh warranty from a more reputable brand. Should it come to that I can recommend replacement options for you.
Best regards, ***** ***** for the news,