Hi community, this week (last week of January 2021), my SmartThings automations have started playing up. I noticed there was a new app release in the past 5 days, but not sure if this is the cause. Main two problems are “Good morning” has just stopped working (based simply on sunrise). Even worse, I have made automations which turn on and off a virtual switch for security armed/disarmed. My automations react to the switch going on or off and sets the appropriate STHM mode. Switching this virtual button now causes the automation to trigger repeatedly evey few milliseconds resulting in 100s of notifcations on my iphone. I should mention I have this virtual switch as I still have intergations with WebCore and can no longer therefore use the old SHM that WebCore used. Is anyone else having these kind of problems in the past week? When this happens, the STHM in the app goes loopy for about 5 minutes and cannot contact the server/ and shows that you have no sensor registered.
The STHM problems are a known issue and there are two different things that can cause it: preconditions having been deleted from your automations, which happened to some people, or changes to the “virtual switch“ DTH, so that you should use the “simulated switch“ DTH instead.
Both of these changes were undocumented and happened at about the same time, which is really annoying. 
See the following thread:
Outage Affecting STHM and some automations (19 Jan 2021)
Also note that SHM is no longer supported, so I suspect you probably meant STHM instead…
FAQ: SHM and STHM are different
If not, you should move over to STHM as SHM is likely to be flaky. but the problem you describe sounds like the one that has been affecting STHM.
The sunset issue is also one that has been reported by multiple people in the forum, but doesn’t seem to be affecting everyone the way the undocumented change to virtual Switches did. see the following (the topic title is a clickable link)
Hey @JDRoberts, many thanks for the helpful sudgestions. Upon further investigation I found my “Good morning” routine had been completely deleted by Samsung. I’ve added it back in with an additional check that I’m at home before running it. Maybe it’ll stay put now.
Also, your sudgestion to move away from Device Type Virtual Switch to Simulated Switch has resolved the issue with STHM firing 100 times each time I toggle the switch.
Thanks agin.