Comment 3 for bug 1902148

Ok I got it.
In:
/snap/libreoffice/current/meta/gui
there is the launcher libreoffice.desktop.

Unfortunately it contains bad actions launchers, as far as I understand that:

Actions=Writer;Calc;Impress;Draw;Base;Math;

[Desktop Action Writer]
Name=Writer
Exec=libreoffice

[Desktop Action Calc]
Name=Calc
Exec=libreoffice

[Desktop Action Impress]
Name=Impress
Exec=libreoffice

[Desktop Action Draw]
Name=Draw
Exec=libreoffice

[Desktop Action Base]
Name=Base
Exec=libreoffice

[Desktop Action Math]
Name=Math
Exec=libreoffice