UserAgent: Mozilla/5.0 (X11; CrOS x86_64 11151.59.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.94 Safari/537.36
Platform: 11151.59.0 (Official Build) beta-channel nocturne

Steps to reproduce the problem:
I've seen this issue with both Firefox and Rstudio. Here's what I do for rstudio:

1. Install Linux in Chrome OS
2. 
sudo apt update ; sudo apt dist-upgrade -y ; sudo apt install gdebi libnss3 r-base -y
curl -O https://s3.amazonaws.com/rstudio-ide-build/desktop/debian9/x86_64/rstudio-1.2.1186-amd64.deb
gdebi rstudio-1.2.1186-amd64.deb
rstudio

What is the expected behavior?
I should get an rstudio window where I can type, and use the backspace key to delete.

What went wrong?
I'm getting key presses seen slowly, or not at all, and occasionally a bunch of repeats as once.

In firefox I had 400 tabs open all of a sudden when I tried to open a tab. I had a constant line of "t"s appear in rstudio even without hitting t, and in rstudio I've also see the menus flashing indicating that it thinks I am holding down the alt key.

Did this work before? Yes The stable version of Chrome OS which was pushed out with the nocturne device release.

Chrome version: 71.0.3578.94  Channel: beta
OS Version: 11151.59.0
Flash Version: 

This makes X apps in crostini unusable, as I don't know if a keypress will be repeated to the point of forcing the app and machine to crash. (Firefox crashed when 400 tabs opened in a matter of seconds and I couldn't close firefox fast enough.)