USPS shipping module - Works while shopping but options not seen in checkout

Hello. I am having an issue where the USPS shipping module calculates rates in Zen Cart without issue, however is not seen at checkout in PayPal.
I have searched posts for hours however did not find a fix. I have tried updating the usps.php file as seen on this forum however this did not resolve the issue. I am on Zencart 1.3.9h.

Any help would be greatly appreciated.

Thanks,
Lou

Please explain exactly what you're seeing vs what you are expecting.

There are two ways to get to a PayPal checkout, and if you use the method that goes there before you've given your completely shipping address to Zen Cart first, there will be no shipping details shown when first visiting the PayPal site. However, despite that, the value will be calculated after the address is supplied, and properly charged when the transaction is actually completed at a later step.

At this point I'm not agreeing that you're actually seeing a bug. But there's a lot of information missing here.

Thank you for your response. What I am seeing is that the USPS module correctly calculates shipping costs in zencart, however these costs are not added in when the customer goes to checkout. Which settings should I post that would be useful in determining what the issue is?

Thanks again,
Lou

I figured out what was wrong, there was a bad file in my modules/payment directory. Payment is added now once paypal returns my customer to my site to complete the transaction.