Adding a library to a project deletes all other libraries in that project

Current project has a dozen libraries, and builds fine. Uploads and works as intended.
I need to add functionality, so first thing I add a new library, using the platformio built in library manager.
I search for the required lib, and add it to the project.
Immediately platformio deletes ALL libraries in the project and only keeps the one I just added.
What am I doing wrong???

Without seeing your platformio.ini - preferred as preformatted text - it’s hard to say