Oh dear. Shelly Inc. writes this is one of their official support methods and links to it. That means someone is untrue. But it doesn't really matter. The bug exists and is being tracked in github, here, and in two closed issues internal to Shelly Inc. Shelly is unfortunately unwilling to admit their faulty design. Which they can fix. But are chosing not to. Firmware can be changed by Shelly inc. They do it often.
Last, "dangerous" is a general English word meaning: likely to cause problems or to have adverse consequences.
There are many "adverse consequence" of their firmware bug to not update voltage as I describe.