the default nuget version is 3:
https://github.com/ansible-ThoTeam/nexus3-oss/blob/ec06f64/defaults/main.yml#L606
nuget_version: v3 # Nexus gui default. For proxies only. One of v2 or v3
however, the nexus_repos_nuget_proxy is created with the url of the v2 repo:
https://github.com/ansible-ThoTeam/nexus3-oss/blob/ec06f64/defaults/main.yml#L622
remote_url: http://www.nuget.org/api/v2
This does not work.
The Nexus GUI suggests using https://api.nuget.org/v3/index.json, which seems to do the trick.
IMVHO this should be adapted in this repo. But if you disagree, How do I override the settings below nexus_repos_nuget_proxy ?