I’ve got a bunch of waves plugins and they use to always appear in the effects vst3.
Now more than half have disappeared.
(They still appear in vst it’s just the convenience of the plugins being sorted by type not brand)
You might need to re scan for presets in Adobe Audition (Effects > Audio Plug-In Manager).
Waves have an article about this - https://www.waves.com/support/how-to-find-your-plugins-in-adobe-audition
I’ve done this several times but they all don’t appear in the vst 3 category
Funnily enough, this also happened to me yesterday and I ended up uninstalling ‘Waves Central’ and re installing it Luckily that did the trick