Catalina 10.15.7 User here. Have latest Driver and License manager as you all described. Still won't recognize either my Ux2 OR my POD XT Live. Flashing red lights. Have tried multiple USB cables, rebooting system, etc. Such a pain in the butt.
I can see Line6 Device manager in my System preferences (bottom left icon in screenshot) but it shows no devices connected when I go to that tab.