STS truck having an issue I haven't seen - Intermittently builds boost

[SMOKINV8]

This one has me stumped, and I'm hoping somebody would give my starter tune on this truck a sanity check. I put in a ridiculously safe tune so we could fire it up and check everything over for any potential issues. Took it out for a brief drive and at first, it would NOT build more than 1psi of boost on a mechanical boost gauge. Finally after pedaling it around 2500 or so, we got it to build the base 5psi setting we were looking for, but it was not consistent at all. Sometimes we could replicate it, sometimes not. When it isn't building boost, the truck just won't hardly rev or accelerate. There's no knock retard and the fueling on the wideband looks decent even though the LTFT's are off of course.

If you look at the attached log file, there's numerous instances where you can see where it did, and did not build boost. I don't have a boost input on my EIO, so the only way to reference if it actually made boost is to note the AFR on the wideband. If it dips into the 10's, that's when it is making boost. Around frames 1250-1300 it was having the no boost issue, so if you want to take a quick glance you can see what it was doing.

2003 Chevy Silverado
LQ9 6.0L engine
Racetronix 44# Injectors
Updgrade valve springs
STS Air:Water Intercooler
Meth Kit (set to kick in at 10psi, so it shouldn't impact anything here)
76mm Turbo Upgrade (swapped in the 67 for trouble shooting, still had the same issue)

I'm hoping I'm overlooking something stupid in the tune, but I went back over it several times and just haven't seen anything I overlooked. Any insight here is greatly appreciated.

[SMOKINV8]

Meant to update this a while back but I forgot. Found a leaky coupler. Replaced it and the problem went away. I don't really understand how it was building boost sometimes, but its fine now.