Do you have custom rules enabled? I'm running the default uBlock Origin (version 1.18.6) on Firefox (60.8.0esr - company machine) and didn't have any problems.

Do you have custom rules enabled? I'm running the default uBlock Origin (version 1.18.6) on Firefox (60.8.0esr - company machine) and didn't have any problems. uBlock reports that it blocked seven requests to four domains (ads-twitter.com, bing.com, facebook.net and googletagmanager.com)