Jerky Scrolling

I use a lot of themes, but this one is very jerky using the page scroll bar.
The sticky menu makes it almost unusable.
Disabling the sticky menu makes is a little smoother, but still very “jerky” and hard to work with. The front page is the worst. I am using it with woocommerce and the shop pages are also quite jerky.

I tried all sorts of caching options using W3TC and cloudflare but nothing seems to help.
Any tips?

Using Free version. Customer seems top like the design, but may have to go with something else as I don’t want to waste money on the Pro version if it’s this jerky.