A similar issue happens with Apple Silicon macs and external monitors since long time ago. A fix I found online [1] is to disable GPU dithering using the Better Display app.

The flickering was so bad in my case that the pixels got stuck for some minutes when it happened.

[1] https://www.reddit.com/r/mac/s/TDOa9Lb5rP

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an hour ago | parent | next [-]

[deleted]

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ProfessorLayton 2 hours ago | parent | prev [-]

I tried that and many other things like changing the default color profile and it and it didn't work. A reboot fixes it for a few days before returning, so it definitely seems like a bug rather than a hardware issue. Both my work MBP (No issues, macos 15) and personal Air (macos26) are apple silicon.

	▲	ErneX 2 hours ago \| parent [-]
		Dang, it worked for me, but my monitor is a 4K BenQ not a Studio Display, must be something else with those then.