UPDATE:

I took everything off from the Turbo inlet up to the airbox and carefully reassembled it, as well as the stock upper IC hoses.

The likely culprit was either the Hallman BC was sticking AND /OR (most likely) The upper IC hose at the the throttle body had become loose. I hadn't done anything in that part of the engine for qiute sometime before this issue started, but it felt a little loose when I went to remove it.

It's holding a 21 psi just fine now. We lost our local 93 octane provider so I'm looking for some better gas before I try anything higher.

In general I think its time for a set fo Samco's, I might even look into a hard Upper IC, but I don't want to lose the full sized battery.

Thanks for all the input and suggestions.