Hello. I have bought a Sony a84j which is known for its good upscaling. I’m trying to use the vero 4k+ to play different contents (720p, 1080p, 4k), but it is always detected as 4k by the tv (which is the resolution that I have set in options). "Adjust refresh rate” is on.
Is there anything that I’m missing to let the tv handle the upscaling?
If you want to output 720p or lower at native resolution you’ll need to use the Kodi whitelist function, and some associated settings. I wrote a guide for this a while back - it may be a bit more than you need to know(!) but have a look and see if it helps:
Ok, I will take a look, it will be useful for sure (but I have a lot of resolution in the white list, even when I didn’t set them); I have indeed some videos in 720p. However, I am still confused about why if I start a 1080p video, the tv still is recieving a 4k signal.
If you haven’t whitelisted any resolutions, but have enabled refresh rate switching, then Kodi is allowed to switch resolution up to match that of the video, but not to switch down. Presumably you have set the Kodi UI to run at 4K, so that’s the only resolution Kodi can now use. If you were to set the Kodi UI to run at 1080p then it would be able to switch between 1080p and 4K, but anything lower resolution would still be upscaled to 1080p.
Note also that you shouldn’t have the Kodi UI running at 4K. The OSMC skin is not optimised to run at that resolution, so it won’t look any better than 1080p, and performance will be worse.
And finally note that everything I just said is discussed in my whitelist guide, so it would have saved me some typing if you’d read it. 
Ok, sorry for that 
. I am right away to read it. Thank you for your time!!