I've been trying to use some custom maps with background (and non-background) images, e.g. to show a server rack image or similar.
When I add the background image, I can drag the relevant nodes over the image once - and then never again. It's like the background image prevents me from clicking on the node icons.
The only way I can move things afterwards is by removing the background image, then moving the icons, then re-adding the background image.
While I can sort-of understand that behaviour for non-background images, it makes little sense for actual background ones?

Edit:
Another thing I noticed while doing this: I cannot edit the text colour "per node, per map". It's a global setting only.
That leads to an issue with maps with bright and dark backgrounds: I can change the global text settings to suit only one, not both.