Trouble connecting M1 MacBook Air to 4K LG 24UD58-B with Display Port

[jdb8167]

The only real issue I've had so far with my M1 MacBook Air is that I can't get it to connect to my 24" LG 4K display with a known good USB-C to Display Port cable. This monitor has worked with other USB-C Macs and iPad Pros with the same cable. But nothing I seem to do with the MacBook Air makes a connection.

I've also been successful at getting a old 2560x1440 Apple Thunderbolt Display working with a TB2->TB3 adapter from Apple (different cable). I'm hoping it is a software issue. I'm wondering if anyone else with a M1 Mac has had any trouble getting a 4K Display Port monitor working.

I'm going to try to work around the problem for now by getting a TB/USB-C to HDMI cable and trying that.

 

[joevt]

If the Thunderbolt port is not working to deliver DisplayPort to the display, then a Thunderbolt dock may do it. The DisplayPort will be transmitted to the Thunderbolt dock as Thunderbolt packets, then the dock will convert the packets to DisplayPort.

HDMI is limited to 8 bpc for 4K 60Hz so you should try to stay with DisplayPort.

 

[jdb8167]

OK, this is weird. I grabbed a USB-C to HDMI adapter and set up the monitor. As expected it just worked.

So then I tried the USB-C to Display port cable again. Now it is working. It is like the MacBook Air needed to be configured via HDMI before the Display Port worked. Very weird. So it is almost certainly a software issue. If anyone else sees something like this, I would love to hear about it.

 

[zicochaos]

Same problem. Random connection to external monitor via USB-C - DP. Works every time via Caldigit TS3-Lite dock.

 

[Kung gu]

OK, this is weird. I grabbed a USB-C to HDMI adapter and set up the monitor. As expected it just worked.

So then I tried the USB-C to Display port cable again. Now it is working. It is like the MacBook Air needed to be configured via HDMI before the Display Port worked. Very weird. So it is almost certainly a software issue. If anyone else sees something like this, I would love to hear about it.

there are driver problems with some DP monitors

 

[jdb8167]

there are driver problems with some DP monitors

I guess this is the downside of Apple designing their own USB-C/USB4/TB3 controller. I assume they'll work it out eventually.

 

[chrfr]

I guess this is the downside of Apple designing their own USB-C/USB4/TB3 controller. I assume they'll work it out eventually.

I've had weird behavior with the LG 24UD58 using DisplayPort when connected to Intel Macs through a Thunderbolt dock too. I think there's some bugs in this particular display itself.

 

[jdb8167]

I've had weird behavior with the LG 24UD58 using DisplayPort when connected to Intel Macs through a Thunderbolt dock too. I think there's some bugs in this particular display itself.

Could be. It was a very cheap 4K display. I bought it because the DTK didn't have Thunderbolt and the only monitor I owned was an old Apple Thunderbolt Display. I never had a problem with the DTK but I also originally configured it with a HDMI cable so that might make a difference.