Another thing that is important has been mentioned by Wayan; the "box to choose the location of the selected images". This box may easily get covered by e.g. the folder from which you select the images.

Also, since you mentioned right-clicking: I don't know what you may have right-clicked on, but the component has not been made to allow right-clicking on the canvas in order to add images.

When I have a problem with drag-drop, I find I can select the container in the Inspector pane and then go to the element tab and added the photo. That always works for me.

If needed, I can do a Zoom session with you and, using a screen share, will see if I can spot the issue.

I also have a quick demo, it isn't that component it's just a normal container set-up, but it's the same way to do it as the component (you don't actually need the component anymore to achieve that way to add images).
the demo is a prelude to a tutorial for making a gallery lightbox type of effect, using the Reveal

It may just point the way and if not then you also have Brians's offer to have a look-see.
here is the link to the demo
https://youtu.be/VAektTNJZkM