Error in display of image dimensions in panel

I have an image element, and the size selected from the media library is 600x600 pixels.
However the pixel size displayed in the panel is that of the original full size image.

The correct size image is actually used in the page, it seems just the value displayed in the panel is wrong.

Image selected (600x600):

Size displayed in settings panel:

Source code showing correct sized actually used (600x600):

Confirmed. It looks like it is always pulling through a reference to the original size. I will note this and have it looked into.