Custom CellRendererText doesn't update cell size

Hi,
I'm trying to do a Cell Renderer that converts a std::deque into a 
string.
So I derivated the CellRendererText and override the snapshot_vfunc.
First I converted the deque to string, updated the property_text and 
called Gtk::CellRendererText::snapshot_vfunc to render the text.
On gtkmm3 it was working as intended, but on gtkmm4 it doesn't update 
the size of the cell and so the string in only partially shown.

Regards,
Pedro Serrano