[Environment:] Browser / Version: Firefox Nightly 65.0a1 (2018-11-27) Operating System: Windows 10 Pro [Prerequisites:] 1. Tracking Protection Basic enabled (Custom > Tracker in all windows > Basic Block List). [Steps to Reproduce:] 1. Navigate to https://people.neilon.software/ 2. Observe top right side bar. [Expected Behavior:] Social media icons are displayed. [Actual Behavior:] Social media icons are not displayed.

The issue is related to `Tracking protection` breakage. Looking at the devtools console, here are the blocked resources: The resource at “https://s7.addthis.com/js/300/addthis_widget.js#pubid=ra-5be4bc3d495c0d0f” was blocked because content blocking is enabled. The resource at “https://www.googletagmanager.com/gtag/js?id=UA-124578174-2” was blocked because content blocking is enabled. So below are the domains to test: - ​s7.addthis.com - ​www.googletagmanager.com I opened the URL in a fresh browser profile (Firefox Nightly 65, uMatrix installed, normal mode) and loaded the page. Social media are not displayed. I disabled the Spoof Referrer option in uMatrix and then WHITELISTED: - addthis.com (including all related domains) - addthisedge.com(including all related domains) and social media are displayed. The other resources didn't help. So in conclusion: - addthis.com is in Social category = [tp-social] - addthisedge.com is in Social category = [tp-social]

Added uMatrix results.