5k GoPro footage shows as 100% on 4k sequence

I have made a 4k sequence (3840 x 2160 frame size) and am dragging 5k (image size 5312 x 2988) gopro clips onto it. As usual, the first time, Premiere asks whether to match the sequence or change the sequence. I click "keep existing settings". What has happened in the past is that the gopro clips are scaled to 72% so that they fit the 4k sequence and I have some scope for zooming and cropping without losing any quality. However, this behaviour seems to have changed and when I follow the above process, the clip shows as 100% in properties (ie I have to scale all the clips down to fit the frame). Is this normal, or am I missing something?

Thank you!

Charles