Hello,
Please check the site admin access, I cannot login.
Please install the free Classic widget plugin if you have not done that yet.
Then try to regenerate “Regenerate the product attributes lookup table” in Woocommerce > Status > Tools: https://take.ms/LGpvf
In addition, please check Woocommerce > Settings > Product tab > Advanced tab and disable Use the product attributes lookup table for catalog filtering.
Best Regards