I have the dashboard lock extension enabled and has been for a while. The only thing I ever used was the IP based restriction. I decided to test it but there seems to be an issue.
My IP is whitelisted and when I used a VPN to change my IP and login, I was able to to without a problem. Is the IP restriction supposed to work with other lock features or is simply supposed to show a 404 page or something? Either way, I was able to log in using a random IP. The IP was detected by the extension.
Using the MainWP Dashboard v4.6.0.1 and Dashboard Lock v4.0.2 I couldn’t reproduce this behavior.
After I added my IP to the allow list, I enabled a VPN, opened a new Incognito browser window, and was blocked from accessing the login page:
Check if you have any exclusions added in the settings of your VPN that might cause your browser to not use the VPN tunnel. Usually, this is called Split Tunneling.