I’ve consistently had an issue for the past year where I can only get both monitors detected when rebooting my Mac with the thunderbolt cable plugged in. This is annoying for me, because I frequently bring my Mac to meetings and every time it is disconnected from the dock I need to reboot it to re-detect the 2nd monitor. Without reboot, only one monitor will ever be detected or sometimes none when the cable is plugged back in (it has never worked once to auto detect both monitors without a reboot). I am using a short thunderbolt cable and two display port cables connected to two DELL monitors at my workstation.
Is this a known issue? I am on macOs Tahoe 26.1 with the Apple M3 Pro chip and 18 GB of RAM
I am sorry to hear that you are running into issues with your TBT3-UDZ, but I would be happy to help diagnose the issue here.
First, can you confirm that you are trying to connect to your laptop using the included Thunderbolt 3 cable that came with your dock? We’ve seen issues arise when a third party cable is used.
Next, some steps we’ll want to take are to perform a power-cycle of the unit to reset its internal hub chipset. We’ve seen that this can often restore the dock back to a working state when one or more of its functions are not quite working. To do this, please follow these steps:
Disconnect all USB peripherals and displays connected to the dock
Disconnect the docking station from host machine, then disconnect the power adapter from power
Leave unplugged for 1 minute for power to dissipate
Connect docking station initially into power only
Connect docking station to host machine, then connect USB peripherals and displays, then test for functionality