@ckbrewer15 Updated jquery as suggested but didn’t solve the problem. Reverted back because it erased the logo display on the PARTNERS page. Took your advice again (call a professional!) and contacted the site designer. Will see what happens. Thanks again for your time & ideas.
@ckbrewer15 Thank you for your comments. The WordPress dashboard says that WordPress and all the plugins and themes are up-to-date. Therefore, according to jQuery Updater plugin, jQuery is up-to-date. Regardless, I find it weird that of the entire website, only 2 of the 10 pages have a mobile menu that does not work.