MacBook WiFi Slow When USB-C Devices Plugged In — How to Fix (M3/M4 Issue)
Mac Tips & Tricks
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MacBook WiFi Slow When USB-C Devices Plugged In — How to Fix (M3/M4 Issue)

KD Sharma
May 2, 2026
0

✅ Quick Answer MacBook WiFi slowing down when USB-C or Thunderbolt devices are plugged in is a real, documented hardware interference issue — particularly on M3 and M4 MacBooks. USB 3.0 and Thunderbolt cables emit electromagnetic interference that overlaps directly with the 2.4 GHz WiFi band. The fastest fix is

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