Hello,

Please first deactivate it, and then go to wp-content and finds and delete the cache folder from there and then check your site after removing the browser cache, I am sure your issue will solve and then again activate the Autoptimize plugin, I think then it will not create any issue because the issue is only the cache folder issue, and if activating the plugin again creates the same issue on your site then I suggest you to do not use that plugin on contact Plugin Author for getting more help on plugin issue.

Best Regards.