Translation pop-up doesn't show up

[refeed]

Hi, I just noticed on my Firefox 66.0.3 (64-bit) that the translation pop-up doesn't show up when I clicked on the button that appears every I select some texts. I've tested this on two of my computers (FreeBSD and Linux Mint, both browsers are synced through Firefox Sync), and still got the same result.

I'm using Google™ Translator version 0.5.4 which is just updated on 5th May 2019 (on my browser). I think it still worked a week ago..

[M-Yankov]

Same with Firefox 67.0 (64-bit), Windows 10. Maybe the click function handler is not attached correctly.