Electron blinking cyan - requires power cycle to reset

I’m seeing a few of my Electrons go into a funky state that requires a power cycle to clear. Just hitting a reset does not do the trick. I must disconnect the battery, remove 5VDC from the VIN pin…generally wait about 10 seconds and all is good for a few months. I’ve seen this on at last 8 different Electrons and they’re running different application code.

I’ve searched the forum for this specific issue, but with no success. The ironic thing is that the devices run fine for months. It seems similar to the key issue, but there’s no intermixed red blink(s).

I am using 3rd party SIMs (AT&T), but doubt it’s the issue, as the power cycle clears things up and the devices connect without issue.

My code does nothing related to SYSTEM MODE. I don’t try to manage the connection in any fashion.

The devices are all running 0.6.1 or 0.6.2