"Try new version" is now forced on us

In April a new version broke Outlook integration, as detailed at https://community.zoom.com/t5/Zoom-Meetings/quot-Use-an-external-calendar-quot-checkbox-setting-no-longer/m-p/175167

But we could unselect "Try new version" and the functionality was restored (first image).  

With the most recent version, the "Try new version" control is gone (second image) and we are forced onto the new version, breaking Outlook integration.

Is there a fix for this?