Multiple projects in same directory (6.0.10)

[m k]

Selecting stuff from left side of the project window didn't go well.
Selecting project first from left and then using only right side icons is fine.

Modifying symbols and footprints is unknown.
I've always picked the "main" project first.

Sub projects I'll start so that after creating one I'll move stuff back from sub directory without the library file.
No idea how the library file is linked elsewhere but this way all self made library stuff remains available.