Kegging Question - Beer aged differently between 2 kegs

[MJBrowny21]

My friend and I brewed a 10 gallon batch of a NEIPA. We split the batch into both of our carboys and added the yeast (2 liter starter split into both). We both followed the same dry hopping and kegged on the same day with a siphon. We both purged the keg and carbed it. They both tasted the same in the beginning. But about 6 weeks later his still pretty much tasted the same and slightly changed in color. My beer got a lot darker and turned into a malt bomb. Anybody have any clue what is going on?

Its a brand new keg, I used Oxyclean and starsan. I dont have a leak in my system.

Any help/advice would be great.

 

[day_trippr]

The beer that went dark suffered from oxidation.