First thing you should try is accessing WooCommerce > Status > Tools and click on Regenerate lookup tables and Clear transients .
This can happen if a certain type of product type is not supported. With a bit of coding, custom product types can be restricted using a code like this one https://d.pr/n/AM7MiF .
When using a plugin that’s dynamically changing the price of the product, the way the product price is discounted, is not “friendly” with WooCommerce’s built-in is_on_sale() or get_sale_price() methods, and in Rey these are essential to calculate the discounts.
Things evolves so depending on the requests, i will try to create some sort of compatibility but it can take some time.