dotnet nuget push fails with -ss & -sk flags when using snupkg symbol format

[brandedoutcast]

NuGet product used: dotnet.exe
dotnet.exe --version: 3.1.201
OS version: Win10 v1909 (18363.815) / Linux Latest on GitHub actions
Worked before? If so, with which NuGet version: No

1. Run dotnet pack --include-symbols -p:SymbolPackageFormat=snupkg -c Release Core.csproj
2. Generates Core.1.0.0.nupkg & Core.1.0.0.snupkg
3. Run dotnet nuget push *.nupkg -s https://mynuget.org/v3/index.json -k xxxx -ss https://mynuget.org/v3/index.json -sk xxxx --skip-duplicate
4. Throws an error File does not exist (*.symbols.nupkg).

FYR
https://github.com/AraHaan/GitInformation/runs/651127299#step:5:67

dotnet nuget push seems to look for .snupkg by default but when using -ss & -sk flags to specify a different source for symbols it looks for symbols.nupkg instead & causes the error

[donnie-msft]

Glanced and did see some code paths that look like may be the culprit.
Hopefully my recent NuGet/NuGet.Client#3140 didn't regress this...