The size difference caused approx $3 cost adjustment. It's the $26 additional handling charge that's the bigger problem.
This page has info for avoiding cost adjustments, including links to each carrier.
https://www.ebay.com/sellercenter/shipping/preparing-your-shipment/packaging-and-measuring
On the FedEx page, these are the possible reasons for additional handling:
https://www.fedex.com/content/dam/fedex/us-united-states/services/Service_Guide_2023.pdf
Refer to pages 99-116 of that PDF.
Too much tape is a common reason for FedEx (and UPS) to slap on a surcharge. "Non-standard" packaging, like too much tape, results in an additional handling surcharge.
Based on the combination of the size adjustment and additional handling, is it possible your box was a bit rounded and bulging @empowelton ? If not, you need to contact eBay CS to appeal the surcharge. Because the label was purchased with eBay's FedEx account, the only way to appeal is having CS do it for you.
(Packaging) Is in non-standard packaging, including any package that:
5) is not fully encased in an outer shipping container;
6) is encased in an outer shipping container not made of corrugated fiberboard
(cardboard) materials, including but not limited to metal, wood, canvas, leather, hard
plastic, soft plastic (e.g., plastic bags), or expanded polystyrene foam (e.g., Styrofoam);
7) is encased in an outer shipping container covered in shrink wrap or stretch wrap;
8 ) is encased in a soft-sided pack (e.g., courier packs, poly bags, and bubble mailers)
that exceeds 18 inches along its longest side or 13 inches along its second-longest
side or 5 inches in height;3
9) is round or cylindrical, including (without limitation) mailing tubes, cans, buckets,
barrels, tires, drums, or pails;
10) is bound with metal, plastic, or cloth banding, or has wheels, casters, handles, or
straps (e.g., a bicycle) (including packages where the outer surface area is loosely
wrapped, or where the contents protrude outside the surface area); or
11) could become entangled in or cause damage to other packages or the FedEx
sortation system.
Package shape and dimensions may change during transit, which can affect the package’s
dimensional weight and surcharge eligibility. If the dimensions change during transit, FedEx
may make appropriate adjustments to the shipment charges at any time. For U.S. express
and ground services, this surcharge applies per piece even if multiple pieces are bundled in
a shipment. We reserve the right to assess additional handling charges for packages that
require special handling or that require FedEx to apply additional packaging during transit.
Additional Handling Surcharge — Non-stackable
A surcharge applies to any freight handling unit of a freight shipment that is non-stackable.
Non-stackable means the freight handling unit cannot be stacked vertically in a safe and
secure manner. Examples include, but are not limited to, non-stackable freight handling
units that: 1) do not have a flat and stable top or base; 2) may be damaged if another piece
is loaded on them; or 3) have flat and stable loading surfaces but are too narrow to safely
and securely support other freight handling units (e.g., 1–2 barrels or drums).
