Welcome to the forums! I am not sure all the things you have tried, but here are my thoughts:
Is the full qr code shown? Sometimes it gets cut off at the bottom and is missing the bottom.
Have you tried different devices?
You are using the Wyze camera to read the phone screen and not the phone to read any qr code on the camera right?
Do you have forced dark mode on your device? Try turning that off or try a different device without it.
I’ve recommended having the phone show the the we code then lay the phone screen up in a table. Now have the camera be in “ready to connect” mode and lay the camera lens down on top of the phone screen. Slowly pick the camera straight up and it should read the code after about 6-9 inches. This helps remove to dark or to light backgrounds around the phone.
What device are you trying to add? What phone are you using? What app version is on the phone?
You tagged the thread as the outdoor camera and as the floodlight. Untill you confirm which you have, here are some quick search finds I located here in the forums of similar issues.