This issue is constant with the new fresh copy i tried on local wp software too.
The add to cart function is disabled. even after selecting the variations, it is still greyed out. This happens to all the products.
Thanks for contacting us and choosing our product!
If you have any issues, the first solution you should try is deactivate plugins that are not required in our theme.
We see your site have an error in Console of the browser: https://prnt.sc/UWN-npDetoAF
and this error come from Jetpack plugin and settings of this plugin can cause the issue.
Please deactivate Jetpack plugin and try again.