USB-C fast charging not working on new PC (Samsung s10+ for the phone). Stumped.

Hello,

I recently built a new PC. The motherboard is a b450 tomahawk max, and it has a usb-c port on the I/O (as well as several usb 3.2 slots).

I've tried charging my Samsung s10+ using both usb-c to usb-c, as well as usb 3.0 to usb-c, and neither provide true fast charging. It says on my lock screen "Fast Charging", but the time frame it gives indicates extremely slow charging.

I'm wondering if there is something I'm overlooking that could help me get true fast charging while my phone is plugged into my pc. When I initially plug it in on the usb-c to usb-c, it gives a fast charging time estimate, but within a second, that disappears and gives a longer time estimate.

https://i.imgur.com/f3zyRO2.jpg

Thanks for any help.