1. Test with a different cable + adapter
Cheap USB-C-to-HDMI adapters from Hafeez Centre are the #1 cause of external display flicker in Pakistan. Borrow a known-good Apple or Anker adapter and test. If flicker stops, the adapter was the problem (replace with a quality one).
2. Check resolution + refresh-rate match
Some 4K displays at 60Hz over single-stream USB-C cause sporadic flicker. System Settings → Displays → check the resolution and refresh rate match your monitor's native spec. Lower to 30Hz if 60Hz flickers — usually it's a cable bandwidth issue.
3. M1/M2 Air dual-display limitation
MacBook Air M1 and M2 (A2337, A2681) only support ONE external display. Trying to drive two via a hub causes flicker on both. M3/M4 Airs and all Pros support 2+ external displays.
4. When the USB-C port is failing
After exhausting cable/hub fixes, the Mac's USB-C port itself may have wear damage. Try other ports on the Mac. If all fail, port repair PKR 6,000–10,000 fixes it.
5. Intel discrete GPU flicker
On 2018–2019 Intel MacBook Pros (A2141), the dGPU is known to flicker external displays as it ages. Symptom: flicker only when running heavy apps, syncs with system load. Fix: GPU reflow PKR 30,000–45,000.