Thanks for the replies guys!

Unfortunately I’m out of town for the week for work so won’t be able to troubleshoot till this weekend.
I’m definitely going to get a borescope and check inside the cylinders to see if I can see anything, but would this only cause on side and not both spark plugs on either side of motor to close shut?

I’ll do a pressure test aswell on all cylinders just Incase the piston is the issue

Also I’ll take a look into the tune because I agree the AFR does seem off
I’d post a pic of the plugs but I’m not sure how to do that on this thread