You may have another plugin different that Yoast that is also adding the second metadescription.
Nothing to do with Primer/Ascension
Did it get sorted out why were you using two seo plugins?
not yet mate!, tried everything. I did not use two SEO plugins
Don't have to be necessarily SEO
Put here the list of plugins you are using... as I said, it doesn't have to be anything to do with Ascension.