Check in Device Manager for any exclamation marks against your Monitor . If there is one then follow the troubleshooting wizard.
Whilst in Device Manager check your graphics card for exclamation marks also.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?