First, is DFM the best module to use in LMS 2.6 for problems?
What I'm seeing on the email notifications is the body doesn't include enough detail. Like it will end with Utilization:.... as if there is a character limit within LMS for email formatting. Is this the case? I would like full detail on any faults/alarms.
I thought you had said your notification group only included switches and hubs. Double-check that the notification group config is the same for both device classes.
As for threshold adjustment, that is done under DFM > Configuration > Polling and Thresholds > Managing Thresholds. For interface utilization, select DFM > System Defined Groups > Interface Groups, and select your desired interface group. Note: if you want to modify thresholds for a customer interface group, it can be found under User Defined Groups.