up squared shut down unexpectedly

Good evening,

I would like to receive some information about your UP2 quad board, the 5Vdc powered version.
We used one for our control system, but we are having some problems.
Sometimes the up goes off by itself and we don't understand what's going on.
Usually, when there is no power supply or the current drops due to anomalous absorption, the board switches off, but when the power supply returns it switches back on automatically.
So we don't think it's a supply voltage problem.
we would like to know if there is any protection routine that the UP can initiate and leave it off, even with input voltage applied.
Perhaps for an overvoltage or undervoltage or for someone else event.