Every time you quit Call of Duty WWII it will reset your Field of View option. This guide will fix this until the developers finally fix it correctly.
Step #1
Go to where you've installed Call of Duty WWII. By default it's C:\Steam\steamapps\common\Call of Duty WWII.
Step #2
Open the players2 folder and open the file user_config_mp in a text editor like Notepad.
Step #3
Find the line seta cg_fov_override and change -1 to the number beside cg_fov.
Step #4
Be sure to save the file.
Do note if you go to the field of view option in the settings it will say 65 but it's not 65. Ignore what it says.