Weird carbonation issue

So I have had an APA kegged and carbed for a while now. I have drank prob 1/3 to 1/2 the keg. I went to pour some for a friend last week and it was completely flat. I have 14psi on it and its holding. My co2 tank is still pretty full after 2 other kegs, so I figure at this point it would be empty if it was somehow leaking. I am just kinda baffled since it was carbed and I was drinking out of it for prob 6 weeks at least. I thought maybe the bottom got frozen but I checked the temp down low and it seemed fine, around 41 (I do have a fan in my keezer). Looking for ideas or troubleshooting tips.

Is it pouring slow? Closed manifold valve?

Manifold is open and set around 14psi. I checked the tank and it's open as well (was going to laugh at myself if it was closed)