Checking the latest MTH Traction Tire file (2020), it shows a DE-0000023 traction tire for a Railking 2-8-0 consolidation. At the top of the DE-0000023 column, it says "DE-0000022 - use this in its place." The DE-0000022 tire has smaller diameter (22 millimeters) and appears to not be offered now. The current tire recommendation is DE-0000023 which has a larger diameter (23 millimeters). I think that might explain your problem. I stocked up on MTH traction tires a few months ago and requested tire sizes from the previous chart. They filled some of my order with slightly larger sizes from the 2020 chart. It seems that MTH no longer offers traction tires in the original recommended sizes and the new ones may be too large. Just a guess on my part but perhaps that's the reason for your problem.
MELGAR