Connectivity issue with 2x Apple Studio Display's and Dell Dock WD22TB4

Question

L0cal_ Author

Level 1

4 points

Connectivity issue with 2x Apple Studio Display's and Dell Dock WD22TB4

Hi there, I am trying to troubleshoot a connectivity issue regarding the Apple Studio Display 27"

Equipment used;

MacBook Pro 16" M1

2x Apple Studio Display 27" 5K

1x Dell Thunderbolt Dock – WD22TB4

The Apple Displays are both connected using the included thunderbolt cables using the 2 thunderbolt ports on the dock. We have 2 ideantical hot stations with this setup, all the users experince their secondary display not connect when they plug into the dock. The fix for this issue is to unplug the thunderbolt cable from the dock and reconnect. This will always resolve the issue. Any ideas?

We have just updated the Dell docks to the latest firmware and all MacBook Pro's are M1 or newer on latest OS. I also have the same dock at home with 2x Dell 4k displays using the 2 thunderbolt ports and have never had an issue.

Cheers,

Josiah

MacBook Pro 16″

Posted on Jul 23, 2025 04:42 PM

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Answer 1

LuxStar

Level 2

312 points

Jul 23, 2025 04:51 PM in response to L0cal_

Hi!

This seems to be a common issue with certain Thunderbolt docks and the Apple Studio Display. Even with updated firmware, not all docks consistently support dual 5K Studio Displays over Thunderbolt, especially during hot-plug or wake from sleep.

Since replugging one of the cables always fixes it, it’s likely a connection initialization issue — possibly power delivery or timing-related.

A few things worth trying:

Connect the Studio Displays in different Thunderbolt ports on the dock and test for consistency.

Wait 3–5 seconds after plugging in before logging in or waking the Mac — sometimes this gives the system time to detect both displays.

If possible, try one Studio Display directly into the MacBook to isolate the issue from the dock.

Confirm the dock is providing full Thunderbolt bandwidth to both ports (some docks split lanes or prioritize one output).

Unfortunately, even with compatible specs, third-party docks can be inconsistent with Apple displays, especially at 5K resolution.

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