2008 ISX major turbo squealing

[389guy]

2008 ISX 685k miles. No mandate for the last 15k miles. I've never seen over 40lbs of boost since removal. But recently it surges up to 50 if I'm heavy into it. ( I immediately back off when that happens) And since then when I get over 32-36lbs it will start to squeal. Like a horrendous metal on metal/nails on a chalkboard screech. But it's intermittent. It only happens about 60% of the time I get over that boost range. And it only surges up to 50lbs when it screeches.
If it doesn't start to screech between 32-36lbs then it will hold 40lbs with my foot to the floor like normal. When it is surging up to 50lbs I've watched Insite and the actuator is sometimes commanded up to 74%. It's also worth noting I have checked the compressor wheel in the turbo for play and free spin and all seems well there however, there is what seems to be a little bit of oil in the pipe right off the charged side of the turbo going towards the charge air cooler (it's black like oil but it's not slick, it's kind of sticky). I am beyond baffled at this and I've already pulled most of my hair out by now.
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