2017 Acadia 3.6L fuel dilution

[MJN]

Not sure what the correct forum this would go in but I've got a new body style 2017 Acadia SLT 3.6L, bought it with just over 29000 miles and have had it for just over a year and currently has 45000 miles on it. I have been running AMSOIL 5w30 Signature Series oil and sent in oil samples for analysis. Each oil analysis has come back flagged for fuel dilution, 3.7 and 3.8%. The first oil change had 7450 miles when sampled and the second had 6880 miles when sampled. I haven't run extended drain intervals simply because of the fuel dilution. I've read a lot that short trips and lots of idle time will contribute to fuel dilution. Ours sees more highway time than town driving and even less idle time. The engine runs fine, no codes, no stumbling or rough idle, no dark exhaust, good power and mileage (26 to 28mpg highway). I'm wondering if the high pressure fuel pump is beginning to leak, it doesn't look that bad to replace and isn't all that expensive for what it is. Is there good way to find out where the fuel is coming from without doing swapnostics and just changing parts? I called my local GMC dealer and they had never heard of any issues or had any Acadia's in for fuel dilution. They did mention Terrain's having fuel dilution but it was due to short in-town trips. Anyone else have this issue?