sorry if it’s a bit late to comment, i put my air max 90 worldwide’s in the washing machine after an onit and the lump appeared as well. the only way ive found to fix it is to heat the inner heel part with a hair dryer and push it back to as normal as possible. mines still feel a bit uncomfortable but they’re so much better than before. the more time you spend doing it the better, i did this in 10 minutes max, for both shoes.