Skoda Karoq Diesel Immobilizer problem

Sounds like an immobilizer fault. I had something similar happen with my Karoq. Does the security light flash on the dash when you try to start it? Did you try the spare key?

Security light does flash. I've only got one key. What exactly was the issue with yours? Was it a car electronics thing, or something simpler?

Flashing security light was the giveaway for me too. Turned out the key needed recoding. I’d take it to a workshop that deals with car electronics. They should be able to sort out the key signal. It’s a pain.

Workshop recoded the key. The key signal was corrupted. The repair was 45€, but the issue is resolved.