Old text popping back up, months after last contact. Looking to make stop!

[AlwaysColtron]

At least 3-6 times a day I'll go thru my Massaging app and see all these old conversations from months ago showing up. I'm talking 1-6 months old, some of which are no longer contacts in my phone. I can see why this feature is useful but I'm looking to make it stop. It's also doing it with old Skype sync'd conversations. I'm on a new Lumia 950, deleted all my old backups from OneDrive's and did a new install when I got this phone. It's not a deal breaker but kinda annoying.