Thank you for the post @Metgatz
no, this is not expected. The destination port should show up the same way as configured in Panorama.
It looks like you are running on Panorama 9.1.X. Personally, I have been running all versions in 9.1 up to the latest and never hit this kind of issue. Could you please confirm what version you are using on Panorama and Firewall side? Are you able to reproduce this issue or was this just one time thing?