Why are you using the Dial patterns wizards at all? For most cases, just type in the patterns you want.
The wizards are useful in two cases:
Your provider requires dialing local calls in a format different from other domestic calls. For example, local calls must be dialed as 7 digits; long distance as 11.
Your provider has unlimited local calling, but you use a different (cheaper) trunk for long distance.
If either of these apply to you, it’s possible that something is going wrong with the lookup on localcallingguide.com. What NPA and NXX did you enter?
You have enabled “Enable The Old Style FreePBX Dial Patterns Textarea” in Advanced Settings, a non-default setting. It appears that the dialplan rules wizard breaks when combined with this setting. Resetting the value in advanced settings, even if only temporarily, will resolve.
Please file a ticket with your findings, but know it’s like to get a low priority. It’s possible a community coder will submit a PR to resolve.