I have the same : very difficult to power off the X7, whatever the the key function. I don't have devices directly connected.
No, Widevine does not work on X7. Tetsed in France with MOLOTOV app. Zidoo is not certified Widevine (see their page)
Trying to run MOLOTOV app to watch TV, it appears that DRM Widevine are missing in the android system. Tested with both available firmwares....
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