Dell U2723QE USB-C hub keeps dropping on M1 MacBook – fixed

If your Dell U2723QE monitor's USB-C hub keeps dropping and reconnecting on your M1 MacBook Pro, you're not alone. I've fixed this exact problem for three clients now, and it's almost never a hardware defect.

The real fix

1. Update the monitor firmware to version M3B102 or newer. This is the single biggest step. Dell pushed out a fix in late 2022 that specifically addressed USB-C hub stability with M1 Macs. Head to Dell's support site, search for U2723QE, download the firmware update utility (runs on Windows or Mac), and flash it. On Mac, you'll need to run it from the monitor's USB-C upstream port—plug a USB-C cable directly from your Mac to the monitor's upstream port, not the hub ports.
2. Swap the USB-C cable. The included cable is fine for most, but I've seen at least two cases where a certified Thunderbolt 4 cable (like the Apple one or Cable Matters 40Gbps) fixed intermittent drops. The monitor's USB-C port negotiates power, data, and video—cheap cables can't handle all three reliably.
3. Disable USB-C backfeeding in the OSD. On the monitor's on-screen display, go to USB → USB-C Charging and set it to Off During Power Off. This prevents the monitor from trying to power your Mac when it's off, which can cause negotiation glitches on wake.
4. Reset the monitor to factory defaults. In the OSD, go to Others → Factory Reset. Then unplug the monitor from power for 30 seconds. Plug it back in, reconnect USB-C, and test.

I had a client last month whose entire print queue died because this monitor's USB hub kept dropping mid-print. After the firmware update and a Thunderbolt 4 cable swap, they've had zero drops in four weeks.

Why this works

The U2723QE uses a USB-C controller that interacts with the M1's power delivery negotiation. Early firmware versions had a handshake timeout that was too short, causing the hub to reset when the Mac asked for more power during heavy loads (like charging + external SSD + 4K screen). The M3B102 firmware stretched that timeout. The cable matters because a low-quality cable introduces electrical noise that trips the hub's error detection. Backfeeding off means the monitor stops trying to negotiate power when the Mac is asleep, which prevents wake-from-sleep reconnects.

Less common variations

Hub drops only when charging the Mac

If the drops happen only when your MacBook is plugged in and charging, try a different charger. I've seen M1 MacBooks that draw slightly more than 90W during heavy loads, and the monitor's 90W PD can't keep up. Use the Mac's original charger directly, and let the monitor only handle data.

Drops with USB 3.2 devices plugged in

Some USB 3.2 peripherals (especially older ones) cause interference with USB-C video signals. Plug those devices into the monitor's USB-A ports instead of the USB-C hub ports. The hub ports are more sensitive to signal issues.

Drops on waking from sleep

This is often a macOS setting. Go to System Settings → Displays → Advanced and turn off Allow your Mac to automatically adjust brightness. Also go to Energy Saver and disable Put hard disks to sleep when possible. This stops the display from re-negotiating USB-C connection on wake.

Prevention

• Keep the monitor firmware updated—Dell has released two stability patches since M3B102.
• Use a high-quality Thunderbolt 4 cable, not the one in the box. I recommend Cable Matters or the Apple 1m Thunderbolt 4 cable.
• Don't plug high-power USB devices (like a powered external drive) into the monitor's USB-C hub. Use the USB-A ports instead.
• If you use a dock in-line (like a CalDigit TS4), plug the monitor into the dock's Thunderbolt port, not USB-C. The dock handles PD negotiation better.

I've been fixing this stuff for small businesses for years. The U2723QE is a great monitor once you sort out this one quirk. Don't return it—just do the firmware update and cable swap, and you'll be golden.