Testing setup Create a course Create 5 users and assign them to the course this way: 1 teacher, 4 students Login as each student and do the following: Got into the course participants and click on the teacher On the teacher profile click on "Message" to start a conversation Send 4 messages to the teacher with texts (where X is different on every student): Student X message 1 Student X message 2 Student X message 3 Student X message 4 Login as the teacher and check that on the message drawer (on the top navbar) appear all conversations and you can read them. Test message mixing in boost Log as the teacher Click on the message drawer icon on the top navbar and then on the "see all" link. Open the "private" messages section and then open as fast as you can all four conversations (it is important to open each conversation before the previous one is loaded to queue connections) Once the last conversation is loaded wait for 20 seconds Check that nothing happens on the messaging. If the bug is still present message will get mixed up in the current conversation. Then click on another conversation and wait also 20 seconds Check that the messages from that conversation are correct and does not have and other messages from another conversations. Repeat step 5 for the 2 remaining conversation. Test message mixing in classic Repeat the same test in the classic theme.