Hmm, I believe this is a browser issue, as mentioned by another user who has had similar problems saving during a fight. Also, I forgot to mention that save files from the old version don't work on the new version. To download the game, you can currently do so as a Patreon member.
Yeah , Just in case you will never let the public download your game , I just download itch app and try playing this game there , and I have to say it's a lot smoother than playing it in browser.
P.S. Sorry I only have around $10USD per month to spare and most of it goes to my Internet bill, so I can't support you on Patreon , it's quite hard to live in a cult village especially a lame one like where I lived.