Launching Orion with a private tab while holding device horizontally results in a blank spot on the edge of the screen

Steps to reproduce the issue:

Set Orion opens with.. to New Private Tab
Close Orion
Hold your device horizontally
Open Orion
Upon opening, the (in my case) left edge of the screen is occupied by a blank margin that affects how websites are displayed
Rotating the device fixes this issue

Video of the issue:

Expected behavior:
Pages should be displayed correctly even when Orion has been launched while holding the device horizontally.

iOS and Orion versions:

1.3.27 (1)