Fixing Wi-Fi That Keeps Dropping After a macOS Update

Wi-Fi that worked reliably before a macOS update and then starts intermittently dropping, reconnecting slowly, or failing to auto-join a previously trusted network afterward is one of the more common post-update complaints, and the cause is much more often stale or corrupted network configuration state than an actual regression in the Wi-Fi driver itself.

Ruling out the router and environment first

Before assuming this is a macOS-side problem, confirming that other devices on the same network aren’t experiencing similar drops rules out a router-side or environmental cause (interference, a router that itself needs a reboot, an ISP issue) that would otherwise waste real troubleshooting time chasing a macOS-specific cause for a problem that isn’t actually specific to the Mac at all.

Checking for the obvious: a stuck or corrupted network location

macOS’s network configuration is organized into “locations” (even if you’ve never manually created more than the default one), and this configuration can occasionally end up in an inconsistent state across a system update. Creating a fresh new location and testing whether Wi-Fi behaves correctly under it isolates whether the existing location’s configuration itself has become the actual problem:

System Settings > Network > (location dropdown) > Edit Locations... > add a new location

If Wi-Fi behaves correctly under a freshly created location, that strongly points at corrupted configuration in the previous location rather than a genuine driver or hardware issue.

Removing and re-adding the Wi-Fi service

A more targeted reset, without creating an entirely new location, is removing the Wi-Fi network service entry itself and re-adding it, which forces macOS to rebuild that service’s configuration from scratch:

System Settings > Network > select Wi-Fi > the "-" (minus) button to remove it,
then "+" (plus) to re-add a new Wi-Fi service

This is a meaningfully more targeted reset than a full location change, and resolves cases where the Wi-Fi service’s own configuration specifically (rather than the broader location) is what’s inconsistent.

Clearing the specific network’s stored configuration

If the problem is isolated to one specific Wi-Fi network rather than affecting Wi-Fi generally (it connects and drops repeatedly at home, but behaves normally elsewhere), removing that specific network from the known-networks list and rejoining it fresh, entering the password again rather than relying on a stored keychain entry, clears out network-specific stored configuration and security handshake state that can occasionally become stale for one particular network without affecting Wi-Fi behavior elsewhere:

System Settings > Network > Wi-Fi > Advanced/Details > select the specific network > "-" to remove it

Resetting the system-level network configuration files directly

For persistent problems that survive the steps above, several underlying system network configuration files can be reset directly, which is a more thorough step than the GUI-level location/service changes:

sudo rm /Library/Preferences/SystemConfiguration/com.apple.airport.preferences.plist
sudo rm /Library/Preferences/SystemConfiguration/com.apple.network.identification.plist
sudo rm /Library/Preferences/SystemConfiguration/NetworkInterfaces.plist

A restart is required afterward, at which point macOS regenerates each of these files fresh, rebuilding its entire understanding of network interfaces and known Wi-Fi configuration from scratch — this is a genuinely more disruptive reset (any custom network interface configuration is cleared, not just the specific problem you’re chasing), which is exactly why it’s positioned as a later step rather than a first response.

Checking for a specific, known incompatibility with your router

Occasionally a macOS update changes specific Wi-Fi protocol behavior (a stricter interpretation of a particular 802.11 feature, different roaming or power-save behavior) in a way that exposes a genuine incompatibility with a specific router or access point model’s firmware — checking the router manufacturer’s support resources for known issues with the current macOS version, and updating the router’s own firmware if an update is available, is worth doing if the steps above don’t resolve the problem, since this class of issue isn’t fixable from the Mac’s side at all if the actual incompatibility lives in the router’s firmware.

Why working through configuration resets before assuming hardware failure makes sense

Actual Wi-Fi hardware failures introduced by a software update are extremely rare — the antenna and radio hardware itself doesn’t change when the OS updates. The overwhelmingly more common cause is exactly the kind of stale or inconsistent configuration state described above, which is why working through these resets systematically, rather than assuming a hardware problem or reflexively booking a repair appointment, resolves the large majority of post-update Wi-Fi complaints.