itch.io

You probably didn't change the settings enough and it is defaulting to the same subfolder. (seeing some old femdom kingdom saves listed checking this out today, for example. "Just set it to browser!" vs the reality of lots of browser game makers). Easier to fact check or prevent this stuff when not using browser only versions.  Not the first game maker to make this technical mistake, won't be the last either. Wouldn't be so bad as a 90+ save slot game instead of a 20 slot game, and browser means no casual copy/paste save backups by users to swap between games more readily when this issue happens.
Could be worse! Some people cause this problem with pay2play games. With a free game it is just "oops, well it happens"