Chevylife88

Hello new to forum and I am experiencing low compression on cyl 7 on my 2011 Silverado I'm running a leak down test in morning but I keep seeing this AFM talk and idk much about it other than its re active fuel management and the little I have read on here but I did have a loose rocker on that cyl took all rockers and pushrods out all seem fine took intake manifold off to find a lot of gas in cyl 7 intake port ? Hoping for a bad valve as I don't want to replace rings and pistons sooo any suggestions or has anyone experienced this issue