70mph driveline vibration

[Kinglenario]

Hey guys, I tried searching this but I can’t find the exact thing.

I have a new (700 miles) 2025 1924 model and I have a driveline vibration that happens from about 68mph to 72mph then starts to go away above that speed. I thought it was the tires at first but I changed the tires and I know they’re balanced well so it’s definitely something with the driveline. Feels like driveshafts and feels more like it’s coming from the rear.

Any input would be helpful. I’d rather not leave at dealer but maybe I will need to.

Thanks