What is up with timed automations?

Everything was working smoothly for weeks (I have two hubs in separate locations under different accounts). Recently, timed automations (e.g. on at sunset, off at midnight) have become unreliable. Most devices behave but some do not switch on or turn off. There is no pattern and the problem occurs on both hubs.

Anyone else experiencing the same?

Yes. Following the thread at My First Automation -- Didn't work as planned