2 out of 3 attempts to copy failed

not working properly on some sites like this:
https://news.v.daum.net/v/20210426063013291

I'm using Firefox 70 and it's not working.

Doesn't work the majority of the time. Trash.

Be AWARE, this is SPAM addon!

Does not work with FF 60.

Loved this add-on since forever, but it's not working now after FF update.

hello,
i use win10 build 1709, FF 57.0.2.
Restarted FF after installation.
Unfortunately, the program does not copy anything to the clipboard.
What can I do?
nice greetings
Bernd

nothing happen

it doesn't appear to work. the current clipboard item is NOT replace with the newly selected item.
ff = 57
CoS = 1.0

I have used several autocopy addons in the past, as well as the about:config clipboard.autocopy.true route...but now none of them work including this one. I have spent a long time searching the ff addon site, and installing/removing autocopy addons, because none of them seem to work with this version of firefox!