That is reporting the Sequence settings, not your footage settings. Select your Sequence tab in the Timeline panel, then go to Sequence menu > Sequence Settings. This will show you what your Sequence is set to and can be modified.
The 1920x1080 might be due to a preset your selected. If you want to export to 1440x1080, 1.333 PAR, then change those settings in the Export Settings (or you can click the Match Source button)