I had a similar problem with our 2003 Toyota 4Runner after I had new tires installed. The vibration would start about 50 mph but after 60 mph it wasn’t as bad. The tire shop “indexed” the tire by turning it 90 degrees on the rim and rebalancing the tire. This solved the problem. Years ago, I had a the same problem with my 1954 Buick. I finally traced the problem to a tire that was out of round. In this case, I replaced the tire.
Your tire shop needs to determine the tire which is causing the problem. You have it down to two.