Oil leak from timing chain cover - 2017 vRS petrol

Hi all,

I've got a 2017 Octavia vRS petrol. At service yesterday they identified a slight leak from what appears to be the rear timing chain cover area.

They cleaned the oil off and told me to bring it back in in 1k miles time to look again, but in the meanwhile:
 

• Has anyone else experienced this? On a quick Google search it sounds relatively common?
• Is it likely to simply be a gasket failure or are there any other things I should be aware of (e.g. crankcase pressure build up causing it?)?

Any thoughts on if I should stick with the main dealer for this one (the car is under the Skoda All-In warranty, but this doesn't seem to cover oil leaks) or find a good local specialist (any recommendations in the West London / Berks / North Surrey area would be welcomed)? My thoughts are that if it's simply a gasket failure then a local specialist will likely do it for less, but if the gasket is a symptom of a bigger issue then it _may_ be covered under the extended warranty, so the main dealer may be better.

Attached is the photo they sent me showing the oil leak. 

Cheers!