Hi there,
Thanks for that , Sounds like an “undocumented enhancement” or otherwise known as a BUG…
Great job sleuthing it out , even if it’s luck, well bad anyway.
“C’mon man” is what I’m thinking to the seeedeneer in charge of this Device image… RTC really 
?I know some folks are on summer holiday there, so send an e-mail to support , so it’s on the radar.
HTH
GL 
PJ