Nuget command line to on premise devops connection closed by remote host

We have a feed in an on premise devops 2019 instance, running on windows server 2016, which we publish our own nuget packages to.

I'm publishing to the devops feed using nuget.exe version 5.5.0.6473 from my windows 10 (build 18363.657) workstation).

nuget.exe" push "MyPackage.4.0.0.nupkg" -source "MyFeed""MyKey"

And I get this error:

Pushing MyPackage.4.0.0.nupkg to 'http://server/tfs/MyFeed/_packaging/974dcc27-8295-4752-a98d-ec56e9382b8d/nuget/v2/'...
  PUT http://server/tfs/MyFeed/_packaging/974dcc27-8295-4752-a98d-ec56e9382b8d/nuget/v2/
An error was encountered when fetching 'PUT http://server/tfs/MyFeed/_packaging/974dcc27-8295-4752-a98d-ec56e9382b8d/nuget/v2/'. The request will now be retried.
An error occurred while sending the request.
  The underlying connection was closed: An unexpected error occurred on a receive.
  Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
  An existing connection was forcibly closed by the remote host

There's been some suggestions that this is due to tls 1.2 support, so I've updated registry keys SchUseStrongCrypto and SystemDefaultTlsVersions and set the values to 1 in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v4.0.30319 and HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft.NETFramework\v4.0.30319 on both my client and server, but the problem has not ben resolved.

Any help appreciated.