Is this a Scott Scale 710? Did you buy it new?

Assuming it is, this is my take. That thing has excellent components so I don't think the bearings are failing in the BB. Because it has a press fit bottom bracket, I'd say it was pressed in crooked and damaged the hole it sits in (made it an oval). This now oval shape will feel tight until it gets stomped on a few times then its loose.

Now, shops don't usually press the bb in for the first time so this may not be their fault originally. It is their fault for the repair. They should have checked to ensure that the BB cup seats were in good shape before pressing in a new BB. It could be a frame warranty claim, so I might take it back and ask about this possibility. If they say no, I wouldn't let them work on it and would call Scott myself to try to work it out. Also, never go back to that shop for work after resolving this issue.