I did not request Priority Mail, but that is the only shipping label I am offered

[lholz]

I requested USPS ground shipping for a small, but heavy box. Ebay seems to only want to print me a Priority Shipping label. I am including a screenshot. (Buyer removed for privacy.) You can see USPS parcel was specified, but the only USPS services listed for the label are Priority flat rate. Can I print and use this label? If not, why is it being offered? 

[threshold.sales.group]

I only see the flat rate envelopes listed, but it may be that eBay doesn't want anything shipping parcel select at this point.  I have multiple parcel select inbound shipments from vendors that haven't moved in the USPS system for six weeks. It's the lowest priority freight in the USPS system and unless you're amazon and skip the USPS distribution centers it is probably at guaranteed eBay INR case for at least the next month. 

[nobody*s_perfect]

Your screen shot looks like you might be in the "Carrier packaging" set of options for label purchase. At the top of that page, under Package, click on the button for "Custom size."  However, there's a good chance that Parcel Select Ground still won't show up.

eBay has decided to phase out access to Parcel Select Ground labels, even though USPS has made no changes in their services or policies, and it's offered by all other online postage sellers including PayPal, endicia, stamps.com, etc. When it's not offered, the shipping label page usually defaults to the first option on the list which is flat rate envelope. You can purchase Parcel Select Ground postage through PayPal at

www.PayPal.com/shipnow

But do compare prices before you do that. For Zones 1 - 4, the USPS online price for Priority Mail is literally 10 cents more than Parcel Select Ground, and for Zones 5 - 8 the difference is less than a dollar. If you're a TRS you get a 3% discount when purchasing Priority labels through eBay, which makes it cheaper than Parcel Select.

IMHO Parcel Select ground should only be offered when necessary such as for hazmat or Oversize packages (i.e., length-plus-girth above the Priority limit of 108 inches).

[teltuooutlet]

When you click on "compare all services" what happens? It should show you all options you can select.