Notes
As pointed out by @Honza during the kick-off meeting for the feature.

Affected versions

• 71.0a1 (2019-09-29)

Affected platforms

• all available

Steps to reproduce

1. Launch Firefox; (if not already)Set devtools.netmonitor.features.requestBlocking to true;
2. Access any webpage, open the DevTools inspector - Network tab;
3. Block any request so that the Blocking UI is enabled;
4. In the Request blocking section set any filter
5. Double click on it to make it editable;

Expected result

• action is performed without any issues;

Actual result

• the filter is toggled on-off

Enhancement suggestions

1. have an edit button for the filter and display on hover as with the removal button;
2. split the Toggle button and text section for the filter into 2 separate ones;

Regression range

• not a regression, only visible after implementation of bug 1580728;

Additional notes

• attached screenshot with the issue;

I've yet to see an accessible way to prevent this effect. What I will say is that this effect doesn't change the eventual checkbox value so it's a gloss issue, not a functionality issue.