I couldn’t find your Room ID, but I think you have a typo above and mean RM_d6Xr7gCKks5Q 
This does happen occasionally, please see this similar issue: Wrong data presented in session - #2 by CWilson .
The best thing to do is to check for active rooms with the LK CLI, lk room list, and if the long-running room is not there, it’s safe to assume this is an issue with the portal. The reported usage will not count towards your plan minutes, and will not incur overcharge.