Working solution to PasswordChecker failing on Exercism infrastructure

Since I seem to be the first one that tried to solve the (quite) new PasswordChecker exercise, I think I should communicate the problem I had. Although I had all the tests passing in my IDE (Visual Studio Insiders), when submitting my solution to exercism via the CLI it failed (I tried it 5 times) with the message "An error occurred while running your tests. This might mean that there was an issue in our infrastructure, ..."
I cannot find anything undesirable in my code (you can watch it in the Community solutions, it is the first one published there), so perhaps the issue is really in the infrastructure.
If I can help with anything like more information (sorry, I don't know anything about exercisms infrastructure or where I would have to look to see if something is broken or not set up correctly) or if the problem has been solved, please contact me.