Woke up to the add-on bug and fixed it quickly with this.
"Update: Mozilla started to roll out a fix for Release, Beta, and Nightly versions of Firefox. The fix uses Mozilla Studies, and you need to make sure that this is enabled to get it. Mozilla notes that you may disable Studies again after the fix is applied and add-ons have been re-enabled. You need to make sure that "Allow Firefox to install and run studies" is checked on about:preferences#privacy."