Can't start any two docker-compose environments after update to Windows 20H2

This was originally filed by user @marcusschroeder as docker/for-win#9999, but as it can be reliably reproduced on Windows 2010 (maybe 2004?) but not 1903, and as it only happens with Windows containers, we believe that it is a bug in the windows container code.

Original report:

Expected behavior
On my computer I use a couple of docker-compose environments with windows containers in parallel. Before the windows update to 2004 or 20H2 it was no problem to start several environments with
docker-compose up either manually or programmatically. It didn't matter if it was the same env with a different name or a completely different one.

Actual behavior
Now, when starting any two docker compose environments, the second one gets stuck in start up until the first is stopped.

Information
Is it reproducible? Yes, even on another computer.
Is the problem new? Yes, it appeared after windows update 1903 to 20H2
Did the problem appear with an update? Yes
Windows Version: Windows 10 Pro 20H2
Docker Desktop Version: 2.5.0.1 / 2.4.0.0 / 2.3.0.4 / 2.5.1.0 (experimental) / 3.0.0.0

The problem appeared after a Windows update from 1903 to 2004 or 20H2 respectively.

I have tried:

different Docker Desktop versions (see above) to no avail.
WSL2 and LCOW

Steps to reproduce the behavior
Use the following docker-compose.yml:

version: "2.4"


services:
  service_a:
    image: mcr.microsoft.com/windows/servercore/iis
    ports:
      - 80


  service_b:
    image: mcr.microsoft.com/windows/servercore/iis
    ports:
      - 80

1. Use Docker Desktop with Windows Container Backend
2. Start first environment with above docker-compose.yml: docker-compose -p first up -d
3. Wait until environment is up (5-10 seconds)
4. Start second environment: docker-compose -p second up -d
   At this point docker-compose appears to be stuck and one of the services show status "created" in docker ps -a
5. Stop first environment in separate terminal docker-compose -p first down
6. Now, the command from 5. continues and the environment becomes healthy and the service status is "running"
   Furthermore:

if I remove the "ports" from the docker-compose.yml this issue does not occur.
rolling back to windows 1903 also fixed the issue for now until the windows update is applied again

My colleague @StefanScherer has reproduced it without docker compose, but with a second nat network as follows:

$ docker network create -d nat first
10851710aef0c9645393c78f5480cc9d8c2309b079e4d8d82f70c9c6f1ee064f
$ docker run -d --network first -p 8004:80 mcr.microsoft.com/windows/servercore/iis
e89d12002a50b22b3628ddaca1ac06e4b34728ea803c7d5250d84721ddf993bf
$ docker run -d --network first -p 8005:80 mcr.microsoft.com/windows/servercore/iis
93adddb1f6213d21d0b8138b3fd47784938c238fa75256c31f7291c8713c57aa

$ docker network create -d nat second
e30d9c556d386408137db45222dc47d989e4c0d49a7f3a051f56ee93fa18c912
$ docker run -d --network second -p 8006:80 mcr.microsoft.com/windows/servercore/iis
f05233268a2e826f79f323659bf1e3a15333cd5d440117e053ccf04ceaf1a2c8
$ docker run -d --network second -p 8007:80 mcr.microsoft.com/windows/servercore/iis
3ea1546125d05b655e89913b5dd6677e3aa58d2e2d6b4f0fe93b1ff091ebb08e

The Docker Cli of the last container does not return to the shell prompt, and in Docker Dashboard the fourth container is in CREATED state.
When I kill one of the first containers (e89d12) then the Docker Cli shows this error message

docker: Error response from daemon: failed to create endpoint serene_bhabha on network second: failed during hnsCallRawResponse: hnsCall failed in Win32: The specified port already exists. (0x803b0013).

The Port 8007 was not used before.