Hello,
We upgraded from Bamboo 6.8.1 to Bamboo 7.2.3 and the Gerrit Code Review plugin stopped working. Unfortunately it is not being updated in the last 5 years.
Last time we had someone from the community help out to fix the issues and provide a working code, which we build:
https://github.com/onepremise/gReview/pull/48
It looks like we will need help again to get the plug-in to work with 7.2.3.