I would suggest forgetting just about everything the people at Petsmart told you. They are in the business of selling equipment and animals. The health of the animals they sell is not so much of a concern for them. If they sold you any colored bulbs, throw them out. If they sold you a UVB that is not a long tube shape, it is no good and should be replaced ASAP. Continue working with KarrieRee as far as lighting and temperature go to get everything sorted out for optimal dragon health. She's the best! Usually, once those things are on point, issues either go away, or they are much easier to pinpoint a solution for.
I am confused about how you are getting your temperatures. You mentioned a meat thermometer, but then went on to say you have a digital probe. Those are not the same thing. I'll post a link for the probe so you can see what is being talking about when someone mentions them.
Zoo Med Reptile Terrarium Digital Thermometer | reptile Bearded Dragon | PetSmart
I know this can all seem rather confusing, especially if you were given the wrong information to start out with. I, and a lot of other people, have definitely been there ourselves! It's a lot all at once, with a big learning curve, but usually smooth sailing once this part is sorted out.