SOLVED: Any timer kills my sketch (ESP core version)

[Gunner]

BTW, I have some example Stepper Motor code here that works perfectly with BlynkTimer.

C++ Blynk (Legacy) - Code Examples for Basic Tasks

#23 - Basic Stepper Motor Control Who says Blynk can’t control Stepper motors… well, OK, I have said it may require fancy non-blocking timing… so here it is (disclaimer, not all that fancy after all ) Yes, it is using the old and decrepit Stepper.h library… only because I was too lazy to learn simple accelStepper commands at this moment I am also controlling a 4.29v 1.8deg NEMA 17 stepper with an equally old L298D motor controller… Hey, I works with what…