[jimmygian]

I had the exact same issue and here is how I (finally!!) resolved it:

I removed the .aax plugin file from the plug-in folder.
I then uninstalled the Melodyne 5 from my computer and restarted the computer.

I went to melodyne's page and removed the licences that were linked to my computer.

Without opening Pro Tools, I re-installed Melodyne 5 and then restarted my computer again (just to be safe).
I opened Melodyne (as a standalone programme) and re-activated the licence.

I then opened my Pro Tools 2022.12.00 and Melodyne Appeared in the dropdown menu.


Hope this helps!