Regression in external display identification. Two identical ASUS XG27UCDMG monitors connected directly to a MacBook Air M5 are incorrectly deduplicated into a single external display. macOS enumerates only one external display despite hardware support for two external displays and independent operation of each monitor when connected separately.
This was fixed in MacOS 27 but the two most recent updates and the latest 27.2.1 have broken it again.