No 4K/UHD when connected to Denon 3600H

I bought a vero4k+ for a friend of mine, and when trying to use it directly to his Denon AVC-x3600H receiver, osmc crashes or at least does not output any video anymore. When removing and inserting powerplug, osmc restarts visually.
We now have the Vero connected through the TV (eArc) and this works ok for now.

Enable SSH access (Settings → MyOSMC → AppStore).
Then when connected to the Denon collect logs via (grab-logs -A) and share the URL

Details regarding how to access the command line interface can be found here on our Wiki: Accessing the command line - General - OSMC

Or just provide logs from your current setup (via Settings → MyOSMC → Log Uploader) so we can check no misconfiguration.

when your vero was connected to the denon avc x3600h receiver with a hdmi cable. There is also another hdmi cable comming out of your denon receiver going into your tv. Which hdmi cable are you using right now to connd t your vero straight onto your tv. Because that cable is doing its work wel according to you. It looks that you need to replace the other hdmi cable it seems that could be the cause of your problems.