Not sure if this is new behaviour or if LR6 has always done this and I've never noticed.
I am currently cropping all my images to 2x3 / 4x6 to upload to a school site (outputting with longest edge as 5400 to make 12x18 prints).
When I cycle between images and go back to one already cropped the aspect name is reset to say original each time rather than 2x3/4x6.
This is extremely confusing as I have no way of seeing if the image has actually been cropped or if I have just forgotten to do it! I'm sure in the past the behaviour has been to keep the chosen crop aspect visible in the panel.