FS20 using a "Das Keyboard"

Before I went out to purchase hardware to fly in FS20 I tried to take a test run using my “Das Keyboard” which is a mechanical keyboard. The program will not let me release the parking brake using the command Cntl Num Delete. I have now tried this with multiple planes and there is no way to release the parking brake. This would seem to be basic functionality and I am surprised that the quality control is so poor with something like this. I cannot even get a plane in the air. I have tested the num delete key and it works fine in other Microsoft programs.