Deleting a "Zombie" Dropbox

Hello,

I have a big issue with DropBox.
I used it a while ago and when I didn't need it. I tried deleting it.
So basically, I deleted only the destop dropbox stuff. I thought it was enough.
But now I have this white weird icon of Dropbox. And recently, a lot of my animation application is telling me that they are lacking memory space even I have a LOT of them. I realized that they are under a "hidden" Dropbox sub-file. i can't seem to find it to delete it. I don't want it and it seems to eat up space sor anything that goes in it without my consent.

Then I tried deleting my Dropbox account online. I did that and... nothing changed for my desktop.

It seems that neither my PC Control Panel or I can find the location of this Dropbox zombie I now have. But it's here and eating a whole lot of my memory space. Here's some picture (in french) showing the only thing i can find on my PC. 

I'd like to delete it forever and free up some space. Unreal Engine keep telling me that there no space but I do ! It seems that the UE5 application is telling my that he's in one of the subfile of DB but when I am checking on Files, I don't see it. It doesn't make any sense.

Could you help me ?

Thanks