Hey @godelski, I had that issue in Firefox 57, but it seemed to have gone away with 58. Just FYI - I tried altering a bunch of `about:config` non-default settings, but none of them helped. Thanks.
Thanks for the reply. I edited my comment to note that I was experiencing this under 57. I don't know if it will continue under 58 because it seemed more like a random issue, but it is good to know I'm not the only one.