2.5 ntopng adding vlan sent CPU to max

[Griffo]

Had a look on Redmine, can see a category for ntop, but not ntopng

I noticed that one core on my firewall was pegged 100% with ntopng. I checked the grafana logs, and it started at the exact time i added a new vlan and corresponding interface.

I looked in ntopng, and it had the interface listed and was recording traffic against it so it was working. However I dont' recall adding that interface in the settings after I added it to the firewall.
I went into ntopng settings and simply hit "save" again and CPU returned to normal.
If it matters, ntopng was already monitoring
igb, igb.20, igb.30, igb.50, igb.99. I added in igb.40 to the firewall which is when it pegged the CPU.

I've tried to replicate it, can't so far but I thought i'd drop the thread in case others see the same.

Now to work out why the CPU stats sent by telegraf seemed to show an increase in CPU usage across the cores when top showed one core pegged and the other 3 idle.