Why would a SecureStack have "Last switch reset caused by power cycle" messaging when it was not power cycled?
Diagnostic message from 'show support' states "Last switch reset caused by power cycle".
Other stack units report this unit as the subject of "Unit Leave" and "Unit Join" messaging.
There was no manual reset of the unit's power feed.
No other device on the same power circuit reset itself.
All Firmware Versions
Regardless of firmware version, the switches may display this message if there was an interruption of system power which triggered a reboot of the switch unit in question (common), or if the cause of the reboot was undefined to the message-generating subroutine (rare).
Investigate any local Surge protectors or quality of UPS battery status / Logs
If the reset is not explainable due to power interruption, then consider taking a single such event under advisement