When I flash my code Boron will turn solid white

[ScruffR]

You can try the new official realeas 0.9.0 to see whether this changes anything.
Also what Boron are you using? (2G/3G or LTE)

With millis() timings it's always better to use (millis() - previousEvent > eventPeriod) instead of precalculating the next trigger time and check for (triggerTime <= millis())
Reasoning behind that can be found in this thread

Millis() and rollover tutorial

The millis() function is handy for timing things with the Particle Photon (and Electron, and Core). It executes very quickly and has a good resolution (milliseconds). From the manual: Returns the number of milliseconds since the device began running the current program. This number will overflow (go back to zero), after approximately 49 days. Note: The return value for millis is an unsigned long, errors may be generated if a programmer tries to do math with other datatypes such as ints. Now…

Any solid colour typically indicates some kind of device OS deadlock which can be caused (amongst others) by ISRs, noInterrupt() calls (possibly in any of the used libraries), concurrent use of shared resources (e.g. HW interfaces) between application and device OS.