I ran into this recently and hope to help those looking to define a custom HTTP port on Axis products running firmware 7.20+. I'm not sure if this applies across the board and/or if it was implemented in a version earlier than 7.20 I experienced this on a couple of different models of camera so I'm assuming it's consistent across the board.
This was not easy to find after looking everywhere in the new GUI. I also was not able to find reference to this being only available in the 'plain config' section anywhere in Axis documentation. I did some digging and wanted to share where I finally located the setting:
- Expand Settings
- Click System
- Click Plain Config
- Select "System" from drop down
- Locate HTTP Port in the upper area
Screenshots: