Why are my older Crocs softer than my newer ones?

They’ve both been worn about equally (about 1 year of continous wear) and are the same style (the original Beach).

(I stopped wearing my old ones because I have a weird gait that causes a hole in the sole of my left shoe to form.)

However, I recently put my old ones back on to do dishes, and noticed that they were much softer and a lot more comfortable than my newer ones, which occasionally chafe and have caused my feet to itch on more than one occasion.

Does anyone know if this has anything to do with colors (the old ones were black, new ones lime green) or with manufacturing location (Different colours are made in different places) or for some other reason that I’m unaware of?

Also, does anyone have ideas for fixing the hole in my Crocs and/or re-treading them?

Thanks so much!