Chris, are you able to narrow the window a little further? I'm trying to determine if it's something specific about 45 as a base (will be very hard to fix) or one of our local changes (may be more amenable)?
If it helps any, I had Facebook Chat on while experiencing the "Like" issue, but it was still on when the issue resolved itself. I've since turned CHAT off and it made no difference; "Like" still works.
TenFourFox 45.4.0 is the last version that works correctly for this Facebook feature. (Whether or not you can talk about 'correct' when it comes to FB's JS is a different question). However, it's not safe to use for security reasons, and I do not recommend using 45.4.0. What I recommend instead (for now) is a workaround: Just click 'Like', without hovering, then move the mouse away quickly. This way you can still 'like' like you used to do before FB introduced the popup feature.
Please don't assume this will be fixed by the next release; there's only one of me and I don't use Facebook personally. I'll try to look into it for anything that jumps out as a possible regression, though.
Nothing personal. But I think it's a flaw in design logistics to build
a browser that is not tested and viable on perhaps the most popular
website on the planet. Even if you never use it personally. Just sayin.
Just to make this clear: Beta versions are released on a regular basis on the blog
Interesting, I am fining 38.10 to be the best latest version on FB and
it displays a message from FB stating "update your browser to enjoy
all of the latest features of FB" which ironically means less of the
browser choking bullshit that they call features. :)