PDC image gone + Xtrons experience - Android headunit

First some info and a little customer review...

I bought an android headunit last autumn (2018), an Xtrons PE98MTVPL, after first trying out a s%#%$#tty Funrover unit.

By all means - AVOID the brand Funrover at aliexpress, ebay etc. It is s%#$$@ait, as well as their service. Got new firmware sent over when complaining about its instability. That bricked it when installed.

Model adapted to Skoda/VAG. I have a 2012 Superb 3t. Originally with a Columbus, which started shutting off intermittently. OEM Eftermontering in Sweden had a theory of battery deep discharge, seen a couple of other times doing similar damage. Tried fw upgrade with no result. Same switching off for various periods 30sec-60mins.

Been very happy with the xtrons. Been solid, big 9" screen, good sound quality, good menus, good canbus/model adaptation (climate info, steering wheel ctrls etc.), the Dab z app works better than the one it came with regarding stored favorites and layout (fm is DEAD in Norway).

I have the sound system upgrade, with a panasonic amp under the driver (LH) seat. Had to pull the battery negative for 20-30mins to make the car/canbus accept the unit, if not, no sound... (same procedure with the first funrover unit). The system needs to search for it on the canbus.

After some weeks, however, the PDC image with the green/yellow/red radar when shifting R disappeared. It was there in the beginning, when i had black screen with reverse camera guidelines responding to the steering wheel angle sensor. Still gone now I got the camera installed(stuff takes time).

Same actually happened on the first android unit, the funrover, but at that point I thought that just was part of that sh^#^tty deal.

Anyone knows what this is?

A canbus frame dropping out due to no response? Pdc works fine audibly both front and rear.