Status / Monitoring does not show correct traffic information

[Crunk_Bass]

I am running a multiple WAN setup and noticed the GUI does not show the correct traffic statistics.
A few hours ago I uploaded files via my WAN2 but it shows the traffic on the WAN1 graph.
The Upload from the time WAN2 was downloading with around 100 Mbit/s is also shown on the graph of WAN1.

WAN1:

WAN2:

Vnstat does show the traffic on the correct interfaces.

Shell Output - /usr/local/bin/vnstat -i igb0 -hg
 WAN1 (igb0)                                                              11:15
  ^                                                     r
  |                                                     r
  |                                                     r
  |                                                     r
  |                                                     r
  |                                                     r
  |  r                                                  r
  |  r                                                  r
  |  r  r                                r              r
  |  r  r                                r  r     r  r  r  r
 -+--------------------------------------------------------------------------->
  |  12 13 14 15 16 17 18 19 20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11

 h  rx (MiB)   tx (MiB)  ][  h  rx (MiB)   tx (MiB)  ][  h  rx (MiB)   tx (MiB)
12    11453.5      272.1 ][ 20      184.1       74.6 ][ 04     3904.6      411.3
13     7039.9      198.2 ][ 21      262.6       95.7 ][ 05    26821.9      559.7
14     2044.4      114.6 ][ 22      528.5      112.7 ][ 06     3556.1      118.3
15     1003.5      108.1 ][ 23      515.0       93.6 ][ 07     1862.8      117.9
16      618.2       95.1 ][ 00     7122.6      181.4 ][ 08      257.6       90.9
17      349.8       79.3 ][ 01     4451.7      133.5 ][ 09      118.4       63.8
18      169.8       81.6 ][ 02     1557.7      116.0 ][ 10      194.6       81.4
19      225.0       80.5 ][ 03     3479.7      154.2 ][ 11      655.6       32.2



Shell Output - /usr/local/bin/vnstat -i igb1 -hg
 WAN2 (igb1)                                                              11:15
  ^           r
  |           r  r  r  r  r
  |           r  r  r  r  r  r
  |           r  r  r  r  r  r
  |           r  r  r  r  r  r
  |  r        r  r  r  r  r  r
  |  r        r  r  r  r  r  r
  |  r     r  r  r  r  r  r  r  r               t
  |  r     r  r  r  r  r  r  r  r            t  t  t  t  t  t
  |  r  r  r  r  r  r  r  r  r  r            t  t  t  t rt  t    r
 -+--------------------------------------------------------------------------->
  |  12 13 14 15 16 17 18 19 20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11

 h  rx (MiB)   tx (MiB)  ][  h  rx (MiB)   tx (MiB)  ][  h  rx (MiB)   tx (MiB)
12    25026.2      832.6 ][ 20    41273.3     1378.0 ][ 04      331.1    13450.5
13     5346.4      171.5 ][ 21    18097.4      633.0 ][ 05     8167.4    12963.6
14    16928.4      638.9 ][ 22       57.8      127.8 ][ 06      585.1     9516.7
15    45951.0     1631.2 ][ 23       91.5      426.6 ][ 07       65.1       25.7
16    45490.7     1694.5 ][ 00       83.2      447.3 ][ 08     5470.0      111.1
17    43936.7     1466.3 ][ 01      262.8     9209.8 ][ 09       65.1       25.0
18    43905.7     1468.3 ][ 02      379.8    14401.4 ][ 10      862.6       40.3
19    44302.4     1464.8 ][ 03      268.1    11841.9 ][ 11       24.4       16.1

Does anyone experience the same behaviour?