"Speed up browsing by disabling add-ons"

Windows 10, Internet Explorer 11; Norton 360, Toolbar, Product Serial Number:  XJX9JQBR3XPG

Just about every day--usually multiple times a day--I get this error message at the bottom of my IE 11 screen:  "Speed up browsing by disabling add-ons."

I get this message whenever "the delay caused by add-ons exceeds 0.20 seconds."

The Norton Toolbar is the only add-on I use; and the delay can be as high as 0.59 seconds.

I'm given the option of disabling the Norton Toolbar; but I don't want to do that.

Is there a reason that the Norton Toolbar is adding nearly a second to page-loading time?

Thank you for your help.