On 11/14 I had submitted a support ticket regarding the variability of scheduled events. The response I received was this:
“Thanks for reaching out. I am not sure if you are aware, but we recently performed a server migration to help manage our increased user base. The major push was performed but we are still moving components over to the new back-end platform. I do not have a timeline at the moment, but this issue should be resolved soon as we finish the migration.”
I also saw this announcement today Changes to Data Persistence for Events in SmartThings. I’m not sure if it’s related to the timing variability, but I’m keeping my fingers crossed!