Page with noindex meta tag is still receiving traffic

Hi everyone!

I'm doing a technical SEO audit for a client which is one of the biggest companies in the country. I found out that some of their most important pages have a noindex tag in them. Some even have wrong canonical tags so I was sure that they are not appearing in the search results. I got access to their search console and confirmed that those URLs are not in Google.

However, they said that those pages were getting organic traffic in Google Analytics. I got access and confirmed that those pages have in fact, organic traffic despite having a noindex tag.

Can anyone share ideas on what could be the possible reason? I've hit quite a roadblock.