First Time Kegging – Metallic Off-Flavor
It could well be slight over carbonation. The carbonic bite can taste kind of metallic or minerally. Try dumping presure from the kegs then shake the kegs and dump again repeat a few times and check your carb level then once it’s down taste the beer.
The other option is to take a sample and decarbonate the beer by stirring until all of the carbonation has evolved. Taste the beer and note any off flavors.