After upgrading WP & Avada Theme Woocommerce Subscriptions not working

I have recently set up a subdomain to upgrade WordPress, Avada and plugins, fix any issues and then transfer to main domain. I still have my main domain without the upgrades to WP and Avada, the plugins are updated.

I am using Woocommerce for programs/products and Woocommerce Subscriptions, both updated on main domain and working fine.

After upgrading WP and Avada with the upgraded Woocommerce and Subscriptions, the Subscriptions is not working. In Woocommerce settings, the tabs for Checkout and Subscriptions are there, but when clicked on are a blank grey page and in the front end the checkout pages do not show.

When I delete Woocommerce Subscriptions from upgraded subdomain, Woocommerce works fine.

I know these are plugins, however, since they are updated and working correctly in previous version of Avada, I believe this is a Word Press or theme issue. But do not know what to look for to fix it.

I really need some help with this. I am at my wits end trying to find a solution. Any help would be greatly appreciated. Thank you, Jillian