A. without suricata and snort
Result:  Wan bandwidth out and Lan bandwidth in have values

B. With snort installed
Result:  Wan bandwidth out and Lan bandwidth in have values

C.  Removed snort and installed suricata
Result:  Wan bandwidth out and Lan bandwidth in have NO values but only Zero values

D. Removed Suricata
Result:  Wan bandwidth out and Lan bandwidth in have values

E. With snort re-installed
Result:  Wan bandwidth out and Lan bandwidth in have values

THEREFORE, I HAVE CHECKED THAT SURICATA REALLY BREAKS THE STATS\TRAFFIC GRAPH WAN BANDWIDTH OUT AND LAN BANDWIDTH IN RESULT VALUES TO ZERO VALUE.

I hope someone has a solution for this problem.