Oh! Is _that_ why the calculator is nigh unusable now? Sheesh, this just shot snap's credibility right out the window. It's faster for me to boot up the node executable and do my calculations there.
The more complete solution is entirely removing snap. I did that long ago, but my process was a little painful. From my logs, it went something like this:
snap list
snap remove <copy-paste packages from above>
sudo service snapd restart # core is tricky to get rid of
sudo snap remove core
snap list # check it's empty
sudo apt install gnome-calculator gnome-characters gnome-logs gnome-system-monitor
sudo apt purge snapd squashfs-tools gnome-software-plugin-snap
rm -r ~/snap
