Issue with wordpress dev site redirecting to live URL

I’ve been working on setting up a dev site so a vendor can look into an issue with one of their plugins, and I’ve reached my wits end with trying to get this working.

The issue is that I copied the directory and database to the dev server and have changed the site_url and home database entries to the dev URL and have added explicit definitions in the wp-config file. Anytime I try to access the dev site, I wind up being redirected to the live site. I’ve looked and can’t find anything beyond those two solutions to fix this issue, so I am hoping that someone can help me find the solution this issue.

Thanks for any and all help you guys can give.