I have a 2017 Range Rover HSC Supercharged. There is a definite rhythmic bumping feeling in my car when accelerating over 50mph (a little more than 1 per second). It goes away when coasting and immediately resumes when foot on the gas. I took it to the dealer and nothing was different when I got it back. It feels just like we are driving over a road or bridge with concrete slabs, but it occurs also on a perfectly smooth road. It is also has several odd bumps whenever I start accelerating from a stop, but that quickly goes away until I reach 50mph.

I clearly need to take it back in to the shop, what can I suggest to get this fixed? Any thoughts? Thanks in advance!