Backup Battery not working with PoE

So I was watching the official pro board installation video and Nate stated that while the board can be powered via PoE, that it is lower power then using the DC jack and that it would be totally fine to use both at the same time increasing the overall power. With this in mind, I have connected both power sources. The problem arises when I bought their backup battery and notice that it would not supply the board with power while the PoE was on (Power on light would be off). Would work just fine as soon as I disconnected PoE. This leaves me in a pickle as I was going to connect 2 tablets to the board for charging where my keypads use to be. Is there a solution to this?   

That doesn’t seem right.
I setup my Pro board with POE and found the current draw from my siren was too high, causing board resets. So used a relay for the siren and added the Konnected battery as well for the siren. I only power the battery charge input for 6 hours/week and when the alarm is triggered. I never see a problem with the power to the Konnected board.
I only charge the battery 3 days a week for 2 hours each to keep the battery from overcharging, though the product says that is not a problem.
I don’t know what could cause the issue you report.