* Fix - Fix page going off center after submitting an invalid form in some themes. * Tweak - WC 5.8 compatibility.
* Fix - Reduce the number of events that trigger an add-on price calculation in the product page. * Tweak - WC 5.5 compatibility. * Tweak - WP 5.8 compatibility.
* Fix - Fix a notice when adding a product with an addon to the cart. * Tweak - WC 5.3 compatibility.
