Hi Bernd,
I’m sorry to hear that you are running into this issue as well. This will be fixed in the next maintenance release, but in the meantime, you can continue using 4.5.9 or also implement the fix yourself in the 4.5.10 version. If you would like to go this route, you can find the fix here. You would need to make the changes shown there in the wp-content/plugins/the-events-calendar/common/src/Tribe/Assets.php file.
I have linked this thread to our internal ticket for this issue, so you will be notified when this has been permanently resolved.
I’m sorry for the inconvenience, but I hope that helps! Please let me know if you have any questions.
Thanks,
Jennifer