html Text area not properly displaying calculated field information on form

We have a form that has worked well for over a year and then suddenly it started randomly displaying incorrect information in a text area on the form. the informationt comes from a calculated field on the form. If you click the selection box a second time the information will change to the correct value. The problem  doesn't happen all of the time I would estimate it is about 40% of the time.

A screenshot has been provided to show the form when the error is present. If the Credit Card or PayPal selection is clicked a second time the form displays the correct value. The same problem occurs if check is selected. The fields in the text box where the installment amounts are displayed are referenced from the installment amount field that is located above the text area shown in the screenshot. That field always displays the correct value It should be noted that the error is always double the correct amount

New Information:

Th same problem is also happening on these forms as well:

Hello Onondagaskiclub,

I'm sorry for the trouble caused to you. 

I did test your form and I am able to replicate the issue you are having. I am still working on your form to figure out the cause of this issue but it is taking time. I will get back to you on this soon.

Thank you!

Thank you

The same problem is also happening on these forms as well:

Hello Onondagaskiclub,

I checked the two forms but it appears to be fine when I made tests. So far I was able to replicate the problem as well on the 1st one which Ashwin tested as well. For the meantime I will discuss with Ashwin this first form and see what we could find.

Thanks and warm regards.

The form is going live tomorrow. I changed the form so it will not display the information in question at all. Not an optimal solution but I cannot take the chance that people who are signing up will be getting bad information. Thank you for your efforts.