network.trr.mode=3 prevents the user from accessing any website after reconnecting to the network

[dcicas]

Affected versions

• Fx 70.0.1 Fx 71.0b12

Affected platforms

• mac OS Ubuntu 18.04 Windows 10 Windows 7

Steps to reproduce Preconditions The Doh add-on is installed and the network.trr.mode pref value is 2. The "doh-rollout.enabled" boolean pref was added with the "true" value.

1. Disconnect from the network.
2. Navigate to the "about:config" page.
3. Navigate to the "about:config" page and change the network.trr.mode pref value to 3.
4. Reconnect to the network.
5. Navigate to the "about:config" page and observe the network.trr.mode pref value.

Expected result

• You are able to navigate the internet after reconnecting and setting trr to 3.

Actual result

• The pref stays at 3 but you can no longer visit websites.

I added a http log here

[maxxcrawford]

Bug filled on Bugzilla. Closing here.