I assumed you were describing your steps in detail and saw no trace of actually releasing a CPU, hence my mistake.
Unfortunately, I am not able to reproduce the said issue in either Chrome, Edge or Explorer. I know of people playing in Opera, Safari and Firefox who did not have such problems with the game. Please let me know what browser you are using, so I can investigate further.
In the meantime, you can try clearing the browser cache, or simply downloading the windows release from the page you linked.