@Frank1455 Couple options, use any or all, as works for you.
Change your checkout to earlier. If it’s now 11, change it to 10:30. Have your cleaners scheduled to arrive at 11.
Put in your checkout note that the cleaners arrive at check out time and will enter the unit to begin cleaning immediately.
Use a type of lock/code system that deactivates the guest code/ability to access the unit after check out time. Advise guest of this.
List in your house rules a charge per hour of late check out. Not a fan of that one myself, as most don’t read house rules, and it may not fix the problem you’re having even if they do. Plus, it’s difficult to collect on.
Also, tell your cleaners not to stand by. They have a job to do, at a scheduled time, and if guests are still in the unit after check out, they are trespassing.