I find that I sometimes reply to a DM on here thinking that I am replying to a topic in the forum as I have spoken to someone in both places. Others have mentioned the same.
Can you find and implement a good way to make it clear to users when they are in the messages area and/or replying to a DM, replying on a forum topic, or even when users are in the Teams pages.
Something like different colour buttons or screen elements, so users instinctively know where they are and what they are doing.
There may be existing solutions, check meta.discourse.com for plugins and themes components