This is most often caused by two different issues:
The Ableton plugin search is stuck
This can be verified by seeing searching for plugins in the bottom of Ableton Live for an extended period of time.
To resolve this issue, open your Settings menu in Ableton Live, navigate to Plug-Ins, and click the Cancel button to the right of the Rescan button.
There is a conflict with an older version of BEAM and CUBE
Ensure all old plugin files are deleted from your VST3 and AU folder, then install the latest version of the plugin.