Hello guys, I made a circuit where I am testing

Question

Hello guys, I made a circuit where I am testing

voltages from 3 Phase input and I have relays to turn off and turn on external contactors, the circuit works but sometimes when I turn off the external contactor it stops working or freezes.

I know the problem is with the very long trace around 10 cm long, which has to be far away from the main area where the microcontroller is so I put it on the side far away, and I know when the power is turned on or off for the relay the electric surge causes it to absorb EM (or something like that) and the microcontroller gets a spike which causes it to freeze.

I'm thinking of putting a 3.3uH inductor near the microcontroller pin, will it solve the problem?