Prior to the release of MacOS Catalina, Logitech had a message saying they'd update MyHarmony to 64-bit. That message has now been replaced with the page below. Is it safe to say
Harmony Remote Not Working: Reasons and DIY Fixes
Official Logitech Harmony One thread | Page 634 | AVS Forum
Logitech Harmony Remote Control Installation Software CD 7.6.0, Free S&H | eBay
Amazon.com: Logitech Harmony Elite Remote Control, Hub and App - Discontinued by Manufacturer : Tools & Home Improvement