Apache OpenOffice has had very little development for years. It is essentially abandonware. The community that originally built OpenOffice split off years ago to create , which is updated monthly, looks slightly more modern, and runs much better on Linux systems. If you are going to go through the trouble of enabling Linux on your Chromebook, LibreOffice is the superior choice in every metric.
Since OpenOffice is largely stale (last major release 2014, security-only updates), the community recommends instead — it’s active, modern, and runs well on ChromeOS. chromebook openoffice
Unless you have a highly specific reason to use OpenOffice, you should use one of these alternatives designed for ChromeOS: Apache OpenOffice has had very little development for years