Red VibraTite has an operational top limit of 165˚F or 74˚C. More than that is required to loosen it.
Your motor is running pretty damn hot if the heat from the windings in the can gets to the rotor that doesn’t physically touch them, and is conducted further to the shaft underneath the pinion, and also gives enough heat to bring the pinion up to a high enough temperature to loosen the threadlock.