In reply to BBT.

WordPress 5.4.x did not automatically update to 5.5 unless you intentionally set it up to do so. You are also admittedly using an outdated and unmaintained plugin. The platform cannot support an old version of jQuery forever. Honestly, it should have gotten this change several versions ago. Your best bet is to stop by the WordPress support forums to see if anyone can help you find a replacement plugin with similar functionality.