Bitbucket & Azure Devops: Stepping over method without symbols

Hi! I have a .NET Standard library hosted in a private Bitbucket cloud repository, which I'm publishing using Azure DevOps pipelines to an Artifacts feed. Currently the build and publish works, and in Visual Studio I can see that a pdb file is loaded for the library. The nuspec file in the snupkg contains a `repository` line with the correct url for the repository. However, when I try to step into a library method VS instead steps over and logs "Stepping over method without symbols".
Files:
*csproj*
```

netstandard1.3
true
false
true
true
true
snupkg
true
...

pdbonly
true



runtime; build; native; contentfiles; analyzers; buildtransitive

...

```

What to check or change from here? Thanks!