I have installed OM V5 M4 from this on Ubuntu 18.04 from this tutorial
https://cwiki.apache.org/confluence/download/attachments/27838216/Installation%20OpenMeetings%205.0.0-M4%20on%20Ubuntu%2018.04%20LTS.pdf?version=5&modificationDate=1588003937000&api=v2,
when moderator writes on chat everybody can see it, students when they write
cant see one another's chat, they even can't see their own chat what is writing
only moderators and also moderator can see student text highlighted in orange
color. Here are screenshots from both moderator and student attached below
