UPS Website strips tracking numbers and replaces with UNDEFINED

I noticed yesterday that UPS website seems to be stripping the tracking numbers out of the url when they are being sent from Drupal. USPS, FedEx and Canada post all seem to work well still.

UPS url's should look like this: https://www.ups.com/track?loc=en_US&tracknum=@tracking_number&requester=WT/trackdetails

But the number gets stripped and then replaced with UNDEFINED. This seems to be happening on the UPS side of things, so i'm wondering if the best solution is to use a third party service for tracking UPS packages?

I set this as a bug report, though I don't really think it's a bug in the code, so much as an issue with some new UPS API.