@Ale19826 If you're having a really big issue with it, maybe let people know that there will be a penalty for late check out if prior arrangements aren't made. You don't even have to use it, nescessarily: just put it there as a deterrant. Airbnb does allow you to levy penalties for overstay. I have successfully collected in the past (although it doesn't come up often in my case).
You could try and word it nicely: something like:
Due to our schedule for cleaning and the enhanced Covid cleaning protocol, late checkouts will be charged a fee of $100 (choose your own amount) per hour for overstay past 11 am. If you require a late checkout, please contact us at least X days in advance and we will do our best to accomodate (if that's something you're interested in offering).
I wouldn't jump right to that option, but if the other tactics don't work, it may be your best bet. Putting a monetary penalty on their actions can be effective.