My listing offered USPS Parcel Select and UPS Ground as shipping options (in that order). When I went to print the shipping label I was directed to a screen that was all about shipping via UPS (you've probabably seen it before ... it has links to create a UPS account, associate it with an Ebay account, and finally a link to go ahead and print a UPS shipping label if I already have a UPS account associated with my Ebay account which I do.) I closed that screen and came at it through "Seller Hub" and "My Ebay Seller Overview" and got that same screen either way - never an option to choose USPS or UPS.
I thought perhaps during checkout the buyer had selected UPS but the dollars did not match - it cost me more to ship via UPS than what I received for shipping from the buyer (regular PayPal payment).
I went into my PayPal account and had no trouble selecting USPS or UPS as shipping choice, but the dollars didn't match there either. As it turned out my least cost shipping choice was UPS through Ebay so I took it, even though it was less that what I received from the buyer for shipping payment.
Anyone else had this problem?