
Are you working in Fixed or Flexi Bus mode?
Project Preferences > Fairlight > Audio Busing Mode
Are the Projects created with version 17 or with earlier versions of Resolve (e.g. version 16)?
Are you able to provide a Project file (without media) that illustrates this behaviour?
Not experiencing this behaviour on macOS as both VST and AU (and Fairlight) plugins are recalled correctly in both Fixed and Flexi Bus Projects.