Pending moderation
[@lt]
Annotated text inside the lyrics is supposed to be highlighted in yellow.
In Firefox, this doesn't work. The annotations are present at the bottom of the lyrics, but the words inside the lyrics are not highlighted.
In Chrome, annotated text is inside an html span with class "annotator-hl":
<span class="annotator-hl" data-annotation-id="xxx">
In Firefox, this span is completely missing. The plain text is directly inside the usual divs that make up the song lines.
Just an example of a random song with annotations:
https://lyricstranslate.com/en/charlie-adamson-dance-goombay-lyrics.html


Firefox still works properly here, even in your example!
There are a whole host of things which no longer work in firefox, but which still work fine in chrome or edge - (maybe because they are allergic to an ad-blocker or some other add-on which I have installed?)
- For example, I can neither fast forward nor back up in a youtube video! Nor can I increase or decrease the scale in google maps. (But both work fine in chrome!)
And as far as LyricsTranslate is concerned, much more recently, it's suddenly become impossible (for me!) to even log in to LyricsTranslate in firefox:
I can enter my user name and password without any problem, but when I then hit the green "Log In" button immediately below those lines, nothing happens! I now have to use chrome in order to access Lyrics Translate!
None of those problems happen for me in Firefox. In regards to the annotations, for me they work on Firefox in the link by @Stefano 8, however I've sometimes found pages with annotations that don't work in any browser.
I've found that my problems with annotations are related to using uBlock origin.
The annotations are not part of the served html page, they are injected into the page by some javascript (I don't know why that's necessary). I guess uBlock is blocking some scripts and not others, since the rest of the site works for me (including login and videos).