Pulling windows base images fails
The problem is twofold:


The Win10 LTSB is on its newest version and Docker has stopped supporting this version.
This stops Docker from updating.
Microsoft has moved to its own container registry and in doing so abandoned support for older Docker versions. So while I was pulling from the right registry it could not find a fitting image.


Solution: get an up-to-date, non-LTSB version of Windows

Additional Info:
While the error message did not help in finding the cause the docker log did:

[WindowsDaemon  ][Info   ] debug: a Windows version 10.0.18363-based image is incompatible with a 10.0.14393 host