ATV31
Logical Input
LI1, LI2, LI3, LI4

This phenomenon can occur when the 24V used for the logical input is connected in some coil of relay or of electromagnet and so on.
It's due to the overvoltage generated by Ldi/dt when you cut a continue voltage on a coil (L).
It's possible to reduce the level of this overvoltage, use LA4KC1B or LA4DE2U.