Screen share in Linux Mint 19.1 Cinnamon

I am using jitsi meet for home schooling, but I can’t share my screen. I am using Linux Mint 19.1 Cinnamon. There is no screen share button in the bottom left corner. It is not that there are errors when sharing the screen, but there simply is no screen share button. This is not because I am not a moderator, because I can share my screen on my Raspberry Pi 4 in the exact same conference. Is there a solution?
Thanks in advance

as a wild guess, maybe there is something special with the specific browser build you use ? can you try with jitsi-electron ?

If it helps, I used Chromium web browser in a Debian 10 desktop. I find this works great with Jitsi.

What browser are you using on Mint?

Is this your own deployment? If not, maybe the school admin prevents it

Hey, thanks for your suggestion. I will try so, because I have Chromium on my Raspberry. I can share my screen there.

Hey, I will do so. I haven’t found anything special about my browser build(Firefox). Thanks for your suggestion.

Hey, I’m using Firefox. Maybe I should have written that in the original post.

Hey, it is not my own deployment, but I’m sure the admin hasn’t blocked it because screen share works fine on other operating systems like Raspbian.

What version of Firefox?