Yes, there are issues with multiple displays on Mac, and has been for quite a while. However, this behavior started after updating BIAB to 2025 and it only affects BIAB. No other things has changed in my setup. FWIW, all three displays are using HDMI. Main display and the first extended display, both 27" monitors, uses HDMI over USB-C. The third extended display, a Samsung 50" TV, uses the dedicated Mac Studio HDMI port. This is the display that BIAB defaults to after updating to 2025, regardless of which display is set to be the main display.

It's the same after rebooting or wake from sleep.

I guess I could start using Spaces and just assign BIAB to a dedicated Space, but then I loose the ability to drag windows across multiple displays.

Stein Tore

Originally Posted by Mike Halloran
Originally Posted by Stein Tore
Hi!

After updating to BIAB 2025, the program and all dialog boxes insists on opening on one my extended displays instead of the main display. If I drag the main BIAB window over to the main display, the dialog boxes still appears on the extended display. This was not the case before updating.

I`m on a Mac Studio M1, Sequoia 15.5. I'm not using "separate Spaces" for the displays.

Any ideas on how to solve this? I`m not a very experienced BIAB user (yet), so please excuse me if this is a obvious setting somewhere which I've missed.

Stein Tore

How many displays?

What are they?

How are they connected (be specific)? USB-C doesn’t mean a thing—it’s a port and not a protocol. The Studio supports Thunderbolt, HDMI and DisplayPort over USB-C plus HDMI from a dedicated port.

Does this still happen after a reboot? Does it change after wake from sleep?

Apple has issues with multiple displays that have never been fixed. Some of them we can control; others are waiting on Apple, unfortunately. After I got my Studio in 2023, I had to demonstrate some of these problems to a group of engineers in Cupertino. Fortunately, the Apple mothership is only two miles away from where I live.