Sometimes, Paypal Error: OrderTotal (Amt): Required parameter missing or "Bad Math" error appear on the checkout screen, whenever FormBuilder has multiple checkboxes with identical words.
The workaround is to change the multiple-checkbox options so that no option is identical to a portion of another option.
Also, it is recommended NOT to use the ampersand (&) sign since it also causes the issue at checkout.
& sing should be replaced with "and" word.
Please see an example screenshot of the previous case: (multiple checkboxes after correction)
In addition, it is possible "to use a separate multiple checkboxes element for the separate options."
In other words, if multiple checkbox options contain a text of a later one, the user will need to move them to a separate element, so it should resolve the issue as well.