Skoda Karoq Diesel Engine Warning Light

Check engine light and higher fuel consumption, sounds like a VANOS issue alright. Has the car been experiencing any low power or engine misfire? Did you check for oil sludge? That can mess with the variable timing system. Could be the inlet camshaft sensor too but more likely a solenoid issue if your fuel consumption is up.

Oil sludge... where should I be looking exactly? And how would that affect the variable timing?

Sludge usually builds up in the oil pan and around the inlet camshaft area. It can block the oil passages that feed the VANOS system, preventing it from adjusting the variable timing properly. If the system can't adjust the inlet camshaft timing, that would explain the increased fuel consumption and the engine light. Probably best to get it checked by a workshop.

Thanks. It was indeed the inlet camshaft solenoid valve as you suggested. Cost me about 250€ to replace.