I've recently replaced my rockers due to a Cambelt tensioner fail. The engine is running ok now but I have a leak I'm struggling to nail down. It looks like it's coming from the camshaft seal but this wasn't leaking previously. I have removed the cam cover and resealed. Someone has mentioned the bearing o-ring but I'm not sure how to source this if that's what it is.
Any help appreciated with suggesting what could be leaking.
Dropbox video link;

https://www.dropbox.com/scl/fi/cdz3a7pzdhz...8&dl=0