Network blocking test pages are failing

[cuba]

Description:

Investigate why the network request blocking tests are failing on the following page: https://dev-pages.brave.software/filtering/network-requests.html

Steps to Reproduce

1. Go to the following page: https://dev-pages.brave.software/filtering/network-requests.html
2. Follow instructions on the page

Actual result:

Instructions are failing

Expected result:

Instructions should succeeding

Reproduces how often: [Easily reproduced, Intermittent Issue]

Easily reproduced

Brave Version:

• Can you reproduce this issue with the most recent build from TestFlight?
• Can you reproduce this issue with the previous version of the current build from TestFlight?
• Can you reproduce this issue with the current build from AppStore?

Device details:

Website problems only:

• did you check with Brave Shields down?
• did you check in Safari/Firefox (WkWebView-based browsers)?

Additional Information