bug: Edit button not responding

[darcywong00]

@terrygibbs was drafting a response to this community site issue
https://community.software.sil.org/t/adding-a-file-information-for-f2-f1-acoustic-space/6688/2

when he ran into issues of the "Edit" button not responding at the final step.

Steps to Reproduce

1. Display a group in F2 v. F1 chart
2. Right-click on the chart and select "Parameters.." to display the "Formants" chart in "Graph Parameters"
3. Click on the first item and then show all 6 default items and it will show 10 other Custom fields for personal use.
4. By pressing the "Edit" button, you can select an unused location such as "Custom 1"
5. You can press the "Edit" button a second time to show a chart where you can add your Vowels