USB 3.0 running at 2.0 speeds on the Acer Nitro 5 laptop

I have an Acer Nitro 5, and its USB ports are very slow. Device Manager shows them as 3.1, but transfer speeds remain low (15 MB/s max). I bought a USB-to-HDMI adapter to use a third monitor, but the system recognizes it as a 2.0 port; this causes significant lag and limits the monitor to 720p resolution, making everything look huge on the screen.

Does anyone know how to fix this? I’ve tried everything—including updating drivers—but nothing has worked; the transfer rate remains low.