My battery doorbell model T8222 just got an update to System 2.1.2.2m_2.1, subsystem 0.0.0.4
The system note says “1.Fix the existing BUG and improve system stability”
Any idea what they actually fixed?
Yeah, existing BUG 
Jk, generally details are not provided. You could send a mail to support@eufylife.com and ask for the details.
Yes, the bug is now better, stronger and faster!