There are always events :UPS: In bypass in response to the bypass switch at the UPS, typically for..

[Evgeny_apc]

Video work in this state

[Evgeny_apc · Accepted solution]

It seems like the problem has resolved. The following actions were performed:
1) PSU board is removed and cleaned of dirt. (Power management board on which the bypass switch is located). Removing this card requires caution, because On the board is a 400 volt capacitor (I do not remember the capacitance). It should be discharged (it did not work on the installed board) through the resistance, it is possible through a voltmeter.
2) The control board UPS (the one with the processor) is removed and cleaned.
3) Updated software AP9631 to the last.
After that, everything is collected. And at the moment the problem with the bypass no longer appears. Which of these actions helped - it is not known.