See attached self contained example.

On macOS, picking on a loaded DAE mesh works with Qt 5.10.1 but not with 5.11.0 or 5.11.1.

Same example works correctly on Linux and Windows with Qt 5.11.1.

From what I understand picking works with 5.11.x on builtin meshes (Torus, Sphere, Cuboid, etc) and on other mesh types (e.g. OBJ)

The problem seems specific to DAE (to my knowledge) and only to macOS.

Triangle or Bounding picking doesn't make any difference. They both don't work.