I’ve recently fitted an AliX “Highline” camera to my Golf 7.5 which I assume is a similar setup and infrastructure to your Octavia. The dynamic reversing lines are about 100mm too narrow compared with the car’s width. It’s not the end of the world for me, though it means I must use the door mirrors in conjunction with the camera when reversing - which is good practice anyway! The problem is caused by the aftermarket camera used in my setup being a wider angle than OEM. I believe the guideline positions can be adjusted in MIB2 using ODIS, VCDS etc, though I can’t advise ‘how’ as I don’t have access to such a scanner. I’m doing some research (which is how I found this thread) and will post here any useful information found. That said, there may be knowledgeable members here with diagnostic scanners who could help.