All Product URLs/Permalinks Destroyed!

I don’t understand how this could happen! After recent updates to WordPress (5.5.1), then WooCommerce, my theme (“Ultra” by Themify), and various plugins, ALL of my products have had their URLs changed so that any/all external links pointing back to my website products are now broken!

The previous, correct URLs had the word “shop” before the particular product name, e.g., https://wehrlipubs.com/shop/piano-practice-and-performance/ or https://wehrlipubs.com/shop/book-of-preludes/.

Now they are https://wehrlipubs.com/product/piano-practice-and-performance/ or https://wehrlipubs.com/product/book-of-preludes/.

I did not manually change my product “permalinks”. And WordPress does not allow me to manually change that segment of the permalinks. Nor did I have any plugin that “adjusted” permalink names in some way. Something was done automatically here without my knowledge or consent with disastrous results!

Please, could anyone tell me 1) how this could have happened and 2) how to “globally” return my product URLs to use the word ”shop”.

Thank you so much! 🙏 🙏