Formula parameters calculating incorrect cell references?

For Column H, Row 4: My Formula Below has calculated the correct answer, ironically, even though the nested IF(((E 4 5 /D4)-1<1, ... somehow referenced cell E45, instead of E4, in the Logical Test Argument for nested IF function. I found that this error persisted in EVERY single cell category that calculated the Percentage Variation between FY16-17 and FY17-18.  I'm still trying to understand how my formula mutated by itself?? Is this common issue with Excel?

Here is the formula I used, with the mutated cell reference " E45 "

=IF(ISERROR((E4/D4)-1),"n.a.",IF(((E4/D4)-1)>1,">100.0%",IF(((E45/D4)-1)<-1,"<-100.0%",((E4/D4)-1))))