Electron pingable but not possible to OTA flash

Strange issue today, I have a Electron 2G that it seems online (by pinging on console), it publish events as programmed but it always fail when I try to OTA flash a new firmware.

Any chance to solve it without have the device physically in my hands?

What version of system firmware is on it, and what version are you trying to flash to it?
How does the OTA fail?

running 0.7.0, sorry misunderstanding it fails when I try to upload a new software not system firmware.

OTA update will require a stable, fast connection for quite some time which may well be impaired by the currently running code on your device. A ping on the other hand is a short one-shot action which can be slipped in between any action your device is performing, so not a good means to check whether OTA should work or not.
Try Safe Mode and see if that helps. If it does, make your code more cooperative.

Strange is that I have exactly the same code on two Electrons that is working well and the same (with the right adjustment) on a Photon.

It looks like the Electron is always powered and ready to reply for a ping even if in the code it should sleep and wake up every 15 minutes (as the others are doing).

I will have a look at it physically when possible, maybe it can clarify the actual state.

Is there option to force a device reset remotely without any code in the software?

No, there is not though this has been a requested feature.