I commented on the Bug in Launchpad but I want to ask you here - what did you do to cause those gsettings warnings?
The:
15:49:34:0306 Gtk Failed to load module "canberra-gtk-module"
15:49:34:0307 Gtk Failed to load module "canberra-gtk-module"
15:49:34:0308 GLib-GIO Settings schema 'org.gnome.software' is not installed
warnings do not appear on a fresh install which makes me think maybe you changed something regarding the Snap-Store or Gnome-Software which caused this issue.
EDIT: the Gtk Failed to load module "canberra-gtk-module warnings do appear but the .org.gnome.software error does not.
Regardless, there isn’t enough information here for us to do anything with. See if you can find a log or dump with more information.