Hello,

First Try to install the classic widgets plugins on your site if you have not:
https://wordpress.org/plugins/classic-widgets/

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.

If you have any questions feel free to contact us.

Best Regards.