First please make sure that it’s actually Wordfence that is locking you out of your site. There are many plugins that offer a “lock out” feature and quite a few of them that don’t work well.
If you are locked out by Wordfence you’ll see a message giving you a reason you’re locked out and explaining how to unlock access to your own site. Whenever the Wordfence firewall locks a user out it provides a “Reason:” with a reason describing why you’re locked out. You can use this reason to determine which firewall rule you need to modify to prevent this from happening in future. If the message only says that you have been temporarily locked out, then you have been blocked by settings in the "login security options" section.
If you post on the forums, make sure you include the “Reason: [explanation]” text or a screenshot of the locked-out page so that we can tell you what to change to prevent getting locked out in future.