Google Disavow Links is not effecting my Moz spam percentage score

Unless you are disavowing links somewhere at Moz, it can't effect the score that Moz produces. When you submit the disavow links to Google, only Google sees that file. Moz doesn't have any access to it. They can't know what you have disavowed, so they won't reduce the percentage of spammy links they have found pointing to your site. From If we put the disavow links in google, does MOZ crawl the same links?

We unfortunately will not detect that a link has been disavowed, this isn’t something we were able to include in the old or new DA models. Since disavowing links doesn't actually remove a link, it just signals to Google that the links isn't important, our crawler will continue to find the link. We are working on having something like that built into Link Explorer, where if you disavow a link in Google, you can also mark it as disavowed in Moz, but I’m afraid that option isn't available yet.

Unless your site has a manual action for spam against it from Google or a significant ranking drop that you think is spam link related, you shouldn't use the disavow tool. Using the disavow tool when your site has good SEO can do more harm than good. Google doesn't penalize sites for having a few spammy links. Google understands that all sites get a few and it typically ignores those links rather than penalizing sites. Using the disavow tool is likely to disavow some links that Google is actually counting and is therefore likely to hurt your rankings. Don't use it unless you have to.