I’ve flown the same area twice with my P4 Advanced. Once at 50m and again at 60m. By my calculations the resolution of the images should be 1.64 cm/pixel at 60m and 1.37 at 50m. The app correctly reports 1.3 for the 50m imagery but reports 2.47 or 2.5 in the native resolution for export and orthomosaic resolution respectively. However when I download the image and view in ArcGis the pixels measure 1.9-ish. I’m testing this on the free Pro subscription so this is what I’d expect.

Why does it report resolutions lower than I’d expect from a P4 advanced? Can it be resolved?

I’m not sure why it would do that.
You could reupload the data set and try it again and see if it is different.