Woocommerce products are not indexing in google

HI

I’m not sure how to fix this or what is causing it.

I have quite a few products that my AHREF report is saying that many pages are NOT INDEXABLE.

There is nothing in robots.txt affecting it
All products should be indexable
Website is indexable in settings so that is not issue

What else do I have to check please ?

It’s about 21000 products. They are just tyres and wheels simple products with meta data on there for search filters.

Thanks
kristin