Hi "TheTester". Many thanks for your reply. I became aware of this bulb issue very recently, when I saw a video on YouTube. I checked both my bulbs (high beam and dipped beam) and they appear to be correctly installed, with the bulb "tang/cutout" at the top for the main/high beam and at the bottom for the low/dipped beam. Neither bulb is loose in its mounting. However, I must confess that I did NOT attempt to remove them!

When I view the two bright silver plastic(?) headlight "cowls" (within the headlight assembly itself) from the top and from the side, both of them are pointing down slightly, when compared to the driver's side units. This suggests that I need to raise the whole internal assembly, and I assume that I do that using that adjustment thingy in my photo above?