Unable to fix unauthorized errors on Nuget restore Follow

Using Rider, whenever I run a nuget restore, I am unable to retrieve the packages that are hosted on my company's network. They come back with 401 - Unauthorized errors.

Navigating to the flatcontainer or source url in the browser, I am prompted for my credentials and am able to successfully pull up the json. I've cleared the nuget caches several times. I've purged and re-entered my credentials into Rider. I can successfully add new packages and even upgrade existing ones, and I've noticed that upgrading a package successfully runs a restore action on the remaining. I've been using this method as a workaround, but it doesn't always work and can sometimes lead to other issues.

Any help I can get on this to fix my restore function would be appreciated.