Trying to type the "squared" character (superscript 2)

[Gablewatts]

Trying to type the "squared" character (superscripted '2') causes the X11 server to crash and reboot on my laptop.

I tried this several times with different text editors and even with XFCE's builtin MousePad text editor, if I open onboard, switch to the numeric keys, click and hold on the "2" key, and then select the superscripted '2' character, the X11 server immediately crashes and reboots.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: onboard 1.4.1-2ubuntu4
ProcVersionSignature: Ubuntu 5.0.0-21.22-generic 5.0.15
Uname: Linux 5.0.0-21-generic x86_64
ApportVersion: 2.20.10-0ubuntu27.1
Architecture: amd64
CurrentDesktop: XFCE
Date: Mon Jul 29 12:12:26 2019
InstallationDate: Installed on 2019-04-17 (102 days ago)
InstallationMedia: Xubuntu 18.10 "Cosmic Cuttlefish" - Release amd64 (20181017.2)
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: onboard
UpgradeStatus: Upgraded to disco on 2019-04-25 (94 days ago)