Have you checked the setting to toggle fast charging on/ off? I've accidentally turned off mobile data before and couldn't figure out why it wasnt working. Didn't even remember being in the menu.
Sometimes it can come unplugged from the brick slightly and have that error. If you haven't already, unplug the brick from the wall, the plug from the brick, and also try restarting the phone. Hope you get it fixed!
Make sure the cables are all tight and secure. Also check your battery settings and make sure fast charge is turned on. Make sure you're actually using a fast charge block.