Help: CNC starts lagging/stuttering after the stepper motors have run for a while

Hi all,
My arduino based CNC which runs using universal gcode sender starts laging after running stepper motors for a while. In this video you should be able to see and hear the issue clearly: . This is the first CNC that i have built and I am having trouble figuring out what the cause is or how I can fix the issue. As you see i have tried to wrap some aluminum foil around one of the stepper motor wires just as an experiment as I was hoping that shielding the wires would help.
Some things to note:

• The laging starts after the motors have run for a while, almost as if there is some buildup of some kind.
• The interval between the interuption increases with time.
• If one pauses the process and then start it up again after a litte while it will work fine for sor some time before it starts laging again.
• There is a slight sound from the other motors even when they are not the ones running(not sure if this is normal)

If someone could help me in the right direction I would really appreciate it. I'm so close it would be amazing if I could get it to run smothly!