[Solved] Electron not booting when power reapplied

I have two identical systems side by side, both running identical firmware and bootloader code. One electron does not boot when power is reapplied. In my application I detect when external power has been lost, and after saving any necessary data, I disconnect the LiPo battery using the BATFET control. Upon reapplying power, the one unit will boot, the other not. if I press the reset button the electron will start as expected. This is not an isolated occurrence and see it on a number of units in the field (which is a problem since the only current recovery method is to open the enclosure and press reset.) Any suggestions regarding whether this is a hardware issue (i.e. variation between batches of Electron) or a software issue (perhaps exposing subtle timing/reset threshold type variation between units)? Thanks.

Let me ping someone that might be able to help, @rickkas7, @ParticleD, or @mstanley are you able to assist?

Solution is to place a large capacitor (I used 100uF - possibly overkill) between the ~RST pin and ground. Seems that the simple RC circuit on board is fine most of the time just not in this case. In future I’ll put an active reset controller on that pin.