Q5 keeps reverting to 720p

[dorol]

Having this behaviour - Q5 keeps reverting to 720p - after every boot.
Changing 720p to 1080p in settings works only until next boot.
If i set display to Optimal, instantly goes to 720p.
Any advice?
In Kodi all is ok.

[futeko.com]

So Kodi displays as 1080p?

That is really strange because Kodi is an app on top of Android so shouldn't be able to set a resolution higher than Android system resolution.

Settings should be:

Settings - more - display. Untick optimal display format.
Settings - more - display. Set 1080p 60Hz or whatever you want resolution to be.

Beyond that maybe try a different HDMI cable.