Wrong result in Availability Report for Ethernet interface

Wrong result in Availability Report for Ethernet interface

When i click the availability report from the interface "snapshot" the report is not working as it should. The report is OK for the "today" time period but shows no data if i change the time period from within the report or directly via the "7days" or "30days" link in the interface snapshot.
 
See attached screenshots.
 
Please advise.
 
Regards,
Daniel