Gadget: MacBook Professional 14-inch, November 2024, Apple M4, 24GB RAM macOS model: 26.4 Beta (25E5233c)
Challenge: When closing the MacBook lid (clamshell mode), each exterior screens begin mirroring one another as a substitute of remaining as separate prolonged shows.
Setup:
- Monitor 1 linked through HDMI port.
- Monitor 2 linked through USB-C port.
- With lid open: all 3 shows work accurately (Fundamental + Prolonged + Constructed-in).
- After closing lid: each exterior screens mirror one another.
Steps to breed:
- Join two exterior screens (HDMI + USB-C).
- Arrange as prolonged shows with lid open.
- Shut MacBook lid.
- Each exterior screens instantly begin mirroring.
Anticipated conduct: Each exterior screens ought to stay as unbiased prolonged shows in clamshell mode.
More information: This difficulty persists throughout macOS 26.3.1 and 26.4 Beta (25E5233c). The beta model was put in particularly as a result of consumer boards talked about that Apple would repair this difficulty within the subsequent launch — nonetheless, the issue nonetheless persists in 26.4 Beta.
BetterDisplay workaround doesn’t resolve the problem. This can be a regression — the setup labored accurately on macOS Sequoia earlier than the final replace.
