Hello,
We checked your site with XStore – http://prntscr.com/gyf82x and default WP theme – Storefront – https://prnt.sc/gyf7ac
As you can see from screenshot even with default theme your site does not give a very good page speed results, so we don’t think that theme is a problem.
Check the answer for other user and follow the instructions https://www.8theme.com/reply/166965/
Regards
