Randy Allen Said:
"Good WiFi signal but NO INTERNET: Tonight I tried to set up a WiFi extender. I gave up after a couple of tries because I didnât want to have any security settings wrong. I unplugged the WiFi extender. [...]"
-------
Range Extender:
Why would you unplug the Range Extender??? Though, maybe N/A, that is a device that amplifies the signal. Signal strength should play no role in unsuccessful connections.
Try the Following:
See what happens when you create a new Administrator user. If it is then connecting, then it is likely something configured in your current user.
Booting into Safe Mode, login items do not run, and corrupted files (i.e. caches) are reset. Once in Safe Mode, wait 30 seconds, then restart the Mac, this time booting up normally.
- Reset your SMC and your NVRAM:
If you can't enter you password correctly, then reset your SMC and your NVRAM. Sometimes changes (i.e. updates) are made to the system and then settings (i.e. keyboard) become corrupted, technically. So, reset both on your Mac. So, reset your SMC and reset your NVRAM. Then, try connecting once more. It might take three tries. to fix this. So, be certain you have the time to do so.