Hello ,
Thank you for posting in the community about the corner edges being too bright. It might be something you can adjust by manually setting the exposure and/or brightness. You can also look at adjusting the lighting/sun settings. There also could be a setting in the Material itself to adjust.
Potentially adjust the Camera > Visual Effect > Contrast and Saturation?
I recommend asking in the Facebook community for further help as many users there will be happy to provide some suggestions.
https://www.facebook.com/groups/twinmotion.community/
Kind regards,
Vincent B.