This is a Vex forum, in case you hadn’t noticed, but I would think you might try the Arduino library for a stepper motor. Or, try an Arduino forum, like this: Stepper Motor Nema 24, Driver M452T, Arduino UNO, Speed control - Motors, Mechanics, Power and CNC - Arduino Forum
This is a Vex forum, in case you hadn’t noticed, but I would think you might try the Arduino library for a stepper motor. Or, try an Arduino forum, like this: https://forum.arduino.cc/index.php?topic=354218.0
This isn’t really the best place for an arduino question, but with that being said, the issue is probably the code for updating the LCD delaying the code to continue driving the stepper motor. You could look for a different kind of driver that actually controls the speed, or use a different type of display that takes less time to update, or use a different microcontroller to drive the LCD.