I'm thinking this could be a problem related to Firejail and/or AppArmor. I'm not familiar with them, but it only sounds logical these sandboxes may be preventing the application from reading memory, a file or opening a network connection.
libc6:i386 is just the 32-bit version of the library, which might have been installed if you've installed a 32-bit dependency (e.g. Wine). Both the libraries are separated into /lib/i386-linux-gnu/ld-2.27.so and /lib/x86_64-linux-gnu/ld-2.27.so, so there's no harm keeping both.
Did this start happening with a kernel update? If so, try booting into an older version of the kernel and see if the segfaults continue. Hold Shift while starting the computer and choose Advanced Options for Ubuntu when the GRUB2 menu appears.
Without knowing was installed from a last known good point, I'm running out of ideas. 