The twitter block issue is caused by Firfox filters. Firefox is working on a fix. The announcement reads as: Hey folks, we are aware of the Twitter issue and our team is working on a fix at the moment.
In the meantime, disabling Enhanced Tracking Protection or changing it from Strict should fix this issue temporarily. Here's how to do that: https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop#w_what-to-do-if-a-site-seems-broken