It CAN be the tire wobbling. Fit between rim and tire isn’t exactly the same on all wheels. Sometimes a tire ends up a little lopsided, not quite centered. Usually there is an ”indicator” line molded into the tire sidewall close to the bead. This line should be close and equally close to the rim the whole way around. If it isn’t, well there’s your problem.
Sometimes you get away easy. That’s when the reinforced base of the valve has gotten caught under the bead. Deflate, push valve in, past the bead and inflate. Sometimes it takes several rounds of tire wrangling to get it to settle. Last I had that issue it took soapy water, a partially inflated tire and a lot of grunting and pulling at the low spot before the tire centered around the rim.
It can also be the rim being out of true. Get the bike off the ground and spin the wheel, keep looking at the distance between rim and the fixed reference of your choice. If that distance changes it’s time to contact the seller.