Method 1: Remove and add the Wi-Fi interface
Erase the Wi-Fi interface: Make sure that Wi-Fi is selected on the sidebar. Click the minus (-) sign just below the left corner of network preferences to remove it. After you remove it, click + on the Interface dropdown, select Wi-Fi, click Create, then click Apply. Here is how:
Follow the steps below to remove and re-add and the Wi-Fi connection:
1. Go to Apple menu > System Preferences > Network
2. Select Wi-Fi and click minus (-) button to remove. And click Apply.
　
3. Now add the Wi-Fi interface by clicking the plus (+) sign. Select Wi-Fi as Interface and click Create. Then Click Apply and exit Settings.
Method 2: Wipe all Wi-Fi Settings
You can also remove all your Wi-Fi settings. This involves deleting all preference plist files associated with wireless settings in macOS. Here is how:
1. Turn off Wi-Fi by clicking the Turn Wi-Fi Off in the menu bar.
2. Go to Finder, click Go, and Go To Folder… (or press Command+Shift+G)
3. Enter the following and click Go
4. /Library/Preferences/SystemConfiguration/
5. This will open a window and select the following files: • com.apple.airport.preferences.plist
• com.apple.network.identification.plist
• com.apple.wifi.message-tracer.plist
• NetworkInterfaces.plist
• preferences.plist
　
　
6. Copy these files to the desktop for a backup (you may restore them later by placing these folder(s) here again) and then delete (move to Trash) them from this folder. Make sure that they are no longer in the SystemConfiguration folder.
7. Empty the Trash. Your Mac will recreate all new preference files for wireless networking.
8. Reboot your Mac by going to Apple menu > Restart
9. Turn on Wi-Fi