Hi Mike,
Thanks for your patience.
We have checked the reported problem and we suspect that you have access to the GetSelectedEventsAsync method on the external button click. If so, we would like to let you know when we click on outside of the Scheduler, the scheduler's focus element will be removed. So that the method returns empty. Could you please share with us the use case scenario with this method? So that, we can check the alternative possibilities and provide the solution.
Regards,
Vengatesh