Blocking ?_mof_data in robots.txt resulted in millions of urls: Indexed though blocked

Hi. I am not the savvy in Magento. I am Tech SEO.

We have a client using magento, large ecommerce site.
We were using the Parameter tool in Google Search Console to block Google from indexing these millions of URLs. But, when Google killed the parameter tool, we erroneously put a
Disallow: /*_mof_*
in their Robots.txt. This resulted in millions and millions of urls being classified as “Indexed, though blocked by robots.txt” which makes sense, since GoogleBot has to be able to crawl the page to see that there is a canonical on these parmater pages.

How do you solve this? Keeping the product parameter urls from being indexed?

https://imgur.com/a/Wpxo2eI

submitted by /u/blmbmj
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