I used chrome. The game window had that 'error symbol' that often happens when things fail to load or crash without crashing the whole page or browser
The auto clicker doesnt have any special settings but its set at the fastest possible speed.
When I switched to firefox that I used before on a different computer without issue it didnt seem to crash even after a few hours but I havent closed it yet so I can't confirm if it saves.
Also on this computer I found that it went into 'idle mode' while using it on both chrome and firefox while auto clicking which might be a quirk of that specific computer but it might be worth noting.
The dev tools console on firefox says things about "[save_file] _write" and "[WORKAROUND] workers error" though Im not sure if that will help much I will try to replicate it on chrome when I have the time