I have the same issue and found this post while searching for a possible solution... Unfortunately, there's no reply yet.
I'm using a Jabra Evolve 30 II while working from home and a Jabra Engage 75 at the office, Jabra Direct verrsion 5.12.06601, Cisco Jabber version 12.9.5.55511 build 305511 and Windows 10 Professional build 21H1 (19043.1586) on a Dell Latitude 5420. Jabra Direct says "Cisco Jabber: Not ready" and I can't pick up or hang up Jabber calls from the headset.