I suggest you check out the GitHub issues for the realm stetho plugin you are using. I just checked online and there are multiple realm stetho plugins so I am not sure what one you are talking about.
The Realm team does not maintain stetho plugins and cannot help you debug that. From my experience using Realm stetho plugins, however, I have found that they do break often when Realm versions change. I suggest checking the GitHub issues for the plugin to find a fix from someone else or create a new issue to get it resolved.