When Google Ads informed you about the infection on the website, getting back to the full recovery (to restore the ads) after infection removal needs a bit of work.
Our experience shows that Google Ads technicians do not scan the live website but the copy from the Google cache. As a result, when you report to them that the site is clean, they often return with the answer that it still shows malicious scripts. Usually, they mention files that no longer exist on the server, or you replaced them with the original versions of libraries/plugins.
In this case, you need to report to Google Support that you cleaned the website, indicated files have been verified and are identical to publicly available packages of specific libraries. Then, after reviewing the case, Google restores ads.