X15 Turbo Actuator failure?

[Josiah Harder]

Its been about a month since I first encountered this issue where my truck would start up and idle very badly with rpms fluctuating greatly and the fuel pedal wouldnt be providing any input past certain rpms and then not at all almost as if I was being derated. I restarted the engine and problem persisted but after shutting down for a couple minutes and starting again the engine ran perfectly. This happened again 2 weeks later and again resolved quickly after restarting the truck. I dismissed these events as random glitches until last week when it really worsened and I was having this issue every other day until finally last weekend I was unable to run my truck at all because it would start up and slowly die. Each time I tried to restart it the truck would run for less time till it would be stalling out almost immediately after start up. I had to get towed to a Cummins shop where they had no clue what to do because they had no active engine codes. What they did have though were inactive codes for the VGT actuator but they were reluctant to even consider that since it was inactive.
I should mention that a month prior to ever noticing the truck running weird on start up I was getting codes for that VGT actuator that would only come up at key on or start up but was told by several shops that it could just be a voltage issue tripping the ECM up. That was before any problems actually occurred so I dont blame them.
Cummins inspected my turbo and my actuator, both functional even voltage tested my actuator I think. They checked my EGR cooler and removed and cleaned EGR valve. All good yet truck still wouldnt run by the end of the day.
Next morning truck started and ran fine even though nothing was done. Cummins replaced my fuel filters preemptively even though they only had 13k km on them and I left the shop with a big bill.

The very next morning I encounter the exact same issue and thought I would need a tow again. I tried restarting the engine several times and waited in between till it finally ran normally and I left it on till I got to the nearest Peterbilt.
One thing I have come to notice and be sensitive to is the sound of the turbo upon start up and how it sounds abnormally loud every time I encounter this issue. If I can hear the turbo spooling louder than normal as soon as the engine is started I know im going to have issues.

I wont always have a check engine warning when I notice the issue so its very odd. But Peterbilt was able to see that for the latest event I did have only 1 code for my VGT actuator though it was inactive.

Peterbilt thinks I will need a new actuator though they havent had the chance to fully diagnose it yet and will be doing that on monday.

Im posting here for your guys input and maybe some suggestions I can do or pass on to the mechanics to make sure they check everything. I cant afford to leave this shop and encounter this problem again on the road requiring me to be towed again.

Ill include links to 3 videos I uploaded to Youtube showing how the truck is running. In the 2nd video you can hear the turbo sound I mentioned which will subside after the truck runs for a bit.
Youll notice the RPMs going up and down but thats not me using the pedal the engine is doing it on its own.

https://youtu.be/BKbpnK2bjpY
https://youtu.be/ZM-omNKXtZI
https://youtu.be/_xSchL7N6Ro

My truck is a 2019 Peterbilt with an X15 efficiency series with 450hp. It has 950,000km on it so its getting quite high up there where I shouldnt be surprised if these things are failing I guess