@atripp
Thanks, I was able to enable the v3 api for my feed. Just in case anyone else stumbles on this the v3 api url was actually https://MY.FQDN/nuget/MYNUGETFEED/v3/index.json. Visual Studio does correctly hide the unlisted versions using the v3 api, thank you.

That was just taken from the response of a Visual Studio to Proget request. Is there a way I can force VS to use the v3 endpoint?

Looks like my package source url is
https://MY.FQDN/nuget/MYNUGETFEED

Which resulted in VS making a GET request to https://MY.FQDN/nuget/MYNUGETFEED/Packages(Id='MYPACKAGEID',Version=''MYPACKAGEVERSION')

Thank you, in my case this is an internal Nuget package that is deployed directly to Proget. I unlisted a package version in Proget and I see the listed property is false via fiddler but it still shows up in a visual studio search. By the way, I just created a new topic for my issue here.
https://forums.inedo.com/topic/3514/unlisted-package-version-still-shows-up-in-visual-studio

I'm using Proget version 5.3.27 (build 18). When I unlist a package version I can still see the version when managing Nuget packages in visual studio. Using fiddler to view the response from Proget I see that the listed property is set to false.

<d:Listed m:type="Edm.Boolean">false</d:Listed>

Does visual studio not look for this property? I assumed that unlisting a package version would hide the version in visual studio Nuget searches?

Was this ever resolved? I'm still seeing this issue on 5.3.27.