Fatal Error class-itsec-lib.php on line 235

Upon accessing my URL (www.motivatedmodels.com) the following error pops up:

Fatal error: Maximum execution time of 30 seconds exceeded in /home/content/a2pnexwpnas02_data01/39/3202439/html/wp-content/plugins/better-wp-security/core/class-itsec-lib.php on line 235

When I disable and delete the plugin, the error still remains (even though I flushed the cache for WP, my web browsers (chrome and firefox on desktop and mobile) and the shared WP hosting server).

When I type in the URL and append /?=nocache=1 it loads the site properly and redirects it to the http:// version. This leads me to believe it is a caching issue related to the plugin but I can’t figure out what is causing the error (although I am losing traffic that is trying to access the www. URL version of the site).

Please advise how to proceed.

Thank you!