Oh, I'm really sorry to hear that. Unfortunately, there's no fix for it with the way Itch treats the upload of WebGL (it gives each upload a new hash, even when simply updating the current version, so the save state does not recognize the new version) and the type of save system I'm using.
If you want to see how the game goes on, I suggest downloading the Windows version so the save will persist even with an upgraded build.
I'm really sorry for the inconvenience.
No worries. These things happen. Definitely seen upgrades kill save files on web builds of things before. Just figured I aught to report it because I didn't know you'd uploaded a new version, so thought it might be another bug.
If all that's changed is a hash value somewhere, and the save file contents are still the same, I could probably hack the save file if I felt like putting in the effort and knew the hashes, etc. But it's probably quicker to just replay it later if I want to see what's next than to figure that out.
Still, overall a nice twist on the sliding maze puzzle game genre.