How to Fix the USB Hub Ports Not Working on the Acer Predator XB283K

The upstream USB data cable is missing — the XB283K's USB 3.0 ports are a downstream hub, not a standalone card reader. They will not work until you also connect one of the monitor's upstream ports (the USB-C or USB-B upstream, whichever your unit ships with) to your PC. Many owners connect only the DisplayPort + power cable, so the hub stays completely dead; this is the single most common reason the XB283K's USB ports appear broken.
Upstream link is data-only but poor quality — even with an upstream cable connected, a low-grade or heavily shielded-but-thin USB 3.0 cable (or a long adapter chain) drops the link to USB 2.0 speeds or cuts out entirely, making high-bandwidth devices (flash drives, headset dongles) fail or run slow.
The monitor is in standby with no active video source — the hub on the XB283K is powered by the monitor's own electronics and typically stays inactive while the panel shows no live input. If no source is turned on or the monitor is asleep, the USB ports may not enumerate devices at all.
OSD/firmware leaves the hub disabled — an unusual OSD power setting, an outdated firmware, or a monitor that never completed a firmware update can leave the USB hub unresponsive even when everything is cabled correctly.

Connect the upstream data cable — check the back of the XB283K for an upstream port (a USB-C upstream and/or a USB-B upstream, depending on which model revision you own). Plug the provided upstream cable from that port into your PC. The USB 3.0 and USB-C downstream ports only relay this upstream data, so without it they show nothing.
Power on a video source — switch the monitor on and make sure it is receiving a live signal (from DisplayPort, HDMI, or USB-C). The hub is most reliable when the panel has an active input; let it come out of standby instead of trying to use the ports while the panel is asleep.
Use a known-good USB 3.0 cable and short wiring — replace the upstream cable with a certified USB 3.0 (or higher) cable no longer than ~3 ft/1 m, and avoid USB passthrough adapters. Confirm the PC's USB port itself works by plugging the same device straight into the PC.
Update the monitor firmware — check Acer's support page for the XB283K for a firmware update and apply it over the upstream/USB-C link following Acer's instructions. A firmware reset also restores the hub's default enabled state.
Reset the OSD and test downstream ports individually — from the OSD choose the reset/factory-default option, then test the USB 3.0 and USB-C downstream ports one at a time with a known-good device. If the ports still show nothing on a second PC with a proper upstream cable and a fresh firmware, contact Acer under warranty — the hub board is faulty.