I brewed this in March hoping for a traditional lagering period and tapped in early September. It’s been in my kegerator since it was kegged with the CO2 hooked up the entire time. Up until recently, all my gas lines were standard vinyl tubing. I think I had major O2 ingress and it is very oxidized. Looking back, I should have unhooked the gas line when carbonation was complete or primed and naturally carbed it. I’m going to re-brew and tap it in a more timely manner to see if it tastes as good as I think it should.What happened?