Are you talking about the resolution option in settings>system>display? If so that should be set at 1080p…
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We recommend people with 4K TVs set their user interface (UI) to 1080p. Kodi’s UI is not optimized for 4K yet and this can put unnecessary demands on your device and can lead to a suboptimal picture quality, as well as potentially cause other issues.
The settings we recommend are as follows…
Settings>System>Display>Resolution> 1920x1080p
Settings>System>Display>Whitelist> (empty) *
Settings>Player>Videos>Adjust display refresh rate>Always or On start/stop
Some televisions may also need, or benefit from, the following being set…
System>Display>Force 4:2:2 colour subsampling> (enable)
With the above settings your UI will be output in Full HD and your 4K content will be output in 4K.
*Information regarding the whitelist can be found here. If you have any doubt, feel free to upload some logs so we can verify that your settings are indeed correct.
If your UI is set to 1080p and your just talking about the resolution of the source file then likely the issue is your playing a format that the Vero doesn’t have hardware decode support for. It would be impossible to say for sure without seeing logs but if your running “things that can’t be named” that wouldn’t be something we can provide support for.