I mean, which specific Android device are you using? Like your phone or tablet model name? Also, could you try running it via Chrome to see if the bug still happen?
I tried playing the game on itch.io using my own Android devices, and every single one was able to access and keep the progress. Since I didn't test it for a super long time, my best guess is that your browser might be automatically clearing your cache. This usually happens due to low phone storage or some kind of aggressive optimization settings on your device.