No idea to be honest, I had looked up the flight status for this route in Feb on the KL website and that is what KL states. I also have no idea how often 8592nd has flowen during the pandemic. It was general advice from me to check all restrictions. Over the last year I have seen so many people being sent away at the check in desk (most old people without a PCR).

I did not check if it is actually not bookable online, sounds strange indeed. So I now tried to make a dummy booking on the app which is possible, so looks like it is a glitch.