2017 Trax 1.4T with P02999 low boost - most likely cause?

My niece has a 2017 Trax she bought new that has 61k miles on it. It has started having performance issues and is throwing code P0299 for low boost. She does not live locally so I can't help her out directly on this.

She has recently had some other work done at a mechanic shop so I told her to check the clamp for the intake to the throttle body first. Is there anything else she can check easily on her own? After googling this issue, there seems to be a lot of turbo replacements. It also looks like there was special warranty coverage added at least on the 2016's (A212338300) but I can't find anything specific to the 2017's. She lives in an area where the dealerships are not the greatest and she is worried they are going to try and take advantage of her. Her mechanic told her to take it to the dealer for this issue. I also sent her TSB PIP5495J that shows some of the potential causes.

If you have a way to scan it watch the boost and map sensor to see if they match. I’ve hear of sensor problems that the data doesn’t match and confuses the pcm

She wound up taking it to the dealership. They told her she needs a new turbo. I had her call Chevrolet customer care and they started a case because there is a special warranty adjustment for the turbo. Her dealer told Chevrolet it was not the item covered in the special warranty (presumably the wastegate actuator). The dealership didn't really give her details other than to tell her "it's not the valve covered by the special warranty, it is the other valve" which implies instead of being a wastegate issue, it is a bypass valve issue.