After dissolving faces, subdivide on the face doesn't work Try making a cube, subdiving a face, dissolving it and subdividing it again. You'll see it doesn't work. This needs to be fixed.
because it's a NGon. dissolving faces doesn't dissolve vertices. if you're in vertex mode, you'll see subdividing won't affect the face but adds vertices (and then edges). It's not a bug, your face is and continues to be a NGon.