You need to uninstall the snap version of Inkscape, which can't access a lot of files on your system and is slower, and update the .deb-packaged version with the one from the official ppa.
Do this:
- Open a terminal
- Uninstall the snap package of Inkscape:
sudo snap remove inkscape
- Install the official Ubuntu package from Inkscape's ppa at https://launchpad.net/~inkscape.dev/+archive/ubuntu/stable:
sudo add-apt-repository ppa:inkscape.dev/stable
sudo apt-get update
sudo apt-get install inkscape