Hello,

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.

If you have any questions please feel free to contact us.

Best Regards