Hi Quietmike , In order to troubleshoot, do you have an example url where this is happening? Thank you for elaborating. Currently the Nightly version of Firefox update more often then the stable releases of Firefox. It is on a rapid release cycle. Do you happen to have the version number of nightly when this started happening? This can help narrow down what edits to look through :-) Also the Telementary data sent on the browsers can help improve the performance. There are also automated tests done to check performance of different platforms. We look forward to your reply.