Does ABV affect carbonation?

For a while I had two kegs in my keezer but last week I added the third and recently I added a fourth. I have a 4 line gas distributer and all my kegs are set to about 12 psi. I slow carbonate them by leaving it 12psi and give them a week to fully carbonate.

For the new kegs, both are on a 5 foot beer line and all four are getting the same amount of co2 from the gas distributer. What I find odd is the one I added recently is spitting foam and pours quickly. The one that has been slow carbonating for nearly a week just barely pours out the tap and is under carbonated even though it's been in longer. The only difference is the recent one that pours fast is an IPA that is around 7% ABV and the week old one that pours slowly is a Belgian strong ale around 9% ABV. Can that be the reason?

All the taps are the same model Perlick and like I said, each of these last two kegs are on 5 foot beer lines. I can't think of a reason for this behavior. It's not a huge deal but it's puzzling. I almost wonder if there is something wrong with the slow keg or the faucet on the slow keg.

I'm pretty sure that force carbonating is not affected by abv.. I'm guessing it would only matter if naturally carbing.

If one is pouring more slowly than the other (and they're all on the same distributor) I bet that there may be a slight obstruction in the keg that's pouring slowly...either sediment or hop particles.

I have a similar setup with 3 kegs all on the same distributor.. when 1 keg started pouring more slowly than the others, it turned out that some sediment got caught up in the intake tube. I cleared it out by just blowing some co2 in to the out post, and it started pouring normally again.

That is a great idea but I tried it and it still seems slow. I am sure the gas went all the way down the beer tube since I could hear the bubbles in the keg (kind of funny). After switching it all back the first pull was violent but after the tube and hose filled up it's still back to a very slow pour.

I wonder if it's the faucet. It is new and I've never tinkered with the faucets. Can you restrict the flow with just the faucet? Seems like there isn't any adjustment to them beyond securing them to the collar. If it helps, this is the Perlick faucet.

I tried to clear the beer tube again by running gas down until I could hear bubbles but it still just trickles out. Carbonation also still seems lacking. I hooked up a picnic faucet and that also runs slow. I have no idea what is going on. I almost wonder if the beer tube is bent but you'd think it would have to be crazy bent to be this noticeable and I don't recall any radical bends in the tube when I cleaned it. Only other thing I can think of is a leak in the keg but I doubt that since it would have to be a big leak and I can't hear anything like that. I'm fairly certain it's not the faucet but only way to prove that is switch the faucet to another keg and make sure it runs OK. I'm really stumped by this one.