BTerminal title not showing on Crostini

(for the Dev Talk post, see here: https://forum.devtalk.com/t/hands-on-rust-warning-when-running-with-brackets-lib-chapter-3/23682)

I have been mainly using the Debian dev environment on my Chromebook for the rust code in the book, And everything worked up till now, However, when I tried running this code: http://media.pragprog.com/titles/hwrust/code/FirstGameFlappyAscii/hello_bterm/src/main.rs I ran into a problem.

First I get this error: xkbcommon: ERROR: Key “< CAPS >” added to modifier map for multiple modifiers; Using Mod3, ignoring Lock
After that, the terminal window does open with the correct text rendered, but the title is not visible.

I cloned the exact same code in Windows 10 and there it works perfectly. It didn’t work in WSL2 at all, but I think that’s because I don’t have an X11 server installed.

I don't know if this is specific to Crostini problem or for all Debian-based distros.

**EDIT**: I forgot this info, but my capslock key is mapped to esc, that might cause the error message, but it doesn't explain why I don't see the title. And I needed to add spaces around the word CAPS or it wouldn't show in the text.