Calculated field not showing results

Calculated field not showing results on pdf after filling the form.

I have a IF formula for checkbox to calculate the sum if each checkbox enabled and checked.

It worked while filling the form.

Here's my IF formula:

if([Item1-fee]="checked", abs([Item 1 Price]), "") + if([Item2-fee]="checked", abs([Item 2 Price]), "") + if([Item3-fee]="checked", abs([Item 3 Price]), "") + if([Item4-fee]="checked", abs([Item 4 Price]), "") + if([Item5-fee]="checked", abs([Item 5 Price]), "") + if([Item6-fee]="checked", abs([Item 6 Price]), "") + if([Item7-fee]="checked", abs([Item 7 Price]), "") + if([Item8-fee]="checked", abs([Item 8 Price]), "")