Firefox window change desktop when I open a pdf document

Hi! Actually I don't know where to ask this question, so I start from here.
I frequently open pdf documents in firefox because I share them via Zoom (I'm a teacher). I use compiz with 4 desktop in a cube, on the first face of the desktop I open Firefox and Zoom and in other facces of the cube I open folders with de documents that I need. Every time I need I rotate the cube and open a document with right click and "open with Firefox".
Up to last month that was working fine, recently I see that when I open the document the whole window where firefox is opened in is moved to the face of the cube where I clicked the document.
Is there any reason for this behavior? Why the window is moved?