MP10 Battery back up?

[Antman]

Hello I have an MP 10 question. I have the battery back up and it is plugged into a switchable power strip. When my home loses power the battery back up does not take over and turn my MP 10 on. But if I power the switch off on the power strip to the MP 10 the battery back up does engage and turn the pump on. It has worked in the past and power outages what could be the issue? Thanks