MacBook Air M1 - Dell Thunderbolt Dock - Two External Monitors are Identical

[brianvictordietz]

I'm trying to connect two external monitors to my MacBook Air M1 through a Dell Thunderbolt dock. Both external monitors are showing identical displays instead of extended display. Please help. I can't seem to figure out how to make them separate extended displays. Thank you!

[rboerner]

Originally Posted by brianvictordietz

I'm trying to connect two external monitors to my MacBook Air M1 through a Dell Thunderbolt dock. Both external monitors are showing identical displays instead of extended display. Please help. I can't seem to figure out how to make them separate extended displays. Thank you!

A quick note, I moved your question into the 'Mac' section of the forum.

With that said, your description suggests that the Dell docking station you are using does NOT have DisplayLink technology inside of it, but rather it has a DisplayPort multi-stream hub inside of it (also known as DisplayPort MST).

If this is in fact the case, this is why the displays are not working as expected. This is because Macs do not support DisplayPort MST devices.

If you can provide the specific model number of the Dell docking station you are using, that will allow us to review the dock's specifications online in order to confirm.

[2020vision]

Originally Posted by brianvictordietz

I'm trying to connect two external monitors to my MacBook Air M1 through a Dell Thunderbolt dock. Both external monitors are showing identical displays instead of extended display. Please help. I can't seem to figure out how to make them separate extended displays. Thank you!

Uncheck mirror displays

Preferences > Display