Will Person changes causes life event trigger even assignment row corrected rather than updated

The formula i have written get the previous assignment working hours and current assignment hours, and if both the hours are does not equal we will trigger the life event.

Now, the issue we are facing is when ever if a core HR admin goes into any assignment record and try's to change any details in assignment page the formula is getting triggered automatically.

Thank You,

Nagaraju Godasi.