To edit a wall corner and change its position, in Infurnia, follow these steps:
Hover over the corner you want to edit until a small indicative circle appears.
Click on the indicative circle.
Click on the accompanying lock icon to unlock the corner.
In the properties panel, locate the "Shift" menu. Here, you can adjust the position of the corner by entering values in the "Shift Right" and "Shift Down" fields. Positive values will move the corner in one direction, while negative values will move it in the opposite direction. Press Enter to apply the changes.