/TRACKDETAILS added to search box for UPS package tracking
When expecting a package from UPS I set up a tab with the tracking number and refresh it to get the current status of the package. This worked for years but the last few years whenever said tab is accessed it has either "/TRACKDETAILS" or "/" added to the tracking number in its search textbox, and of course UPS generates an error for it. If I remove the offending characters and search then everything is fine, but if I leave the tab and come back the offending characters are back. It is always one of the two I mentioned, and it will always have one of them. I have no idea if this is a Firefox problem or not but UPS told me to go-away-the-problem-isn't-on-our-end. I'm at my wit's end to solve this, have you any insight to give? Thank you.
P.S. I should add that I have tried disabling all my various add-ons to no avail, it makes no difference.