I'm also seeing problems with the data flow monitor. I'm on VDSL, but it's a flaky connection, so I've got it failing over to a WAN2 backup - wondered whether that confused matters perhaps.
The data flow monitor reflects some traffic - I'll see some machines using large chunks of bandwidth at times, so it's not completely broken. But right at the moment I'm listening to a 128k internet radio stream, and the data flow monitor says my machine is using 0k inbound and 2k outbound. If I hit 'Block' the stream dies, so the router knows it's my stream - it just doesn't count it. My totals at the bottom also say 2k/0k.
It appears it's not counting traffic properly, which also means it's not throttling busy connections as I need. For example, on my previous 2820n I could throttle the kids' machines so I could have a VoIP conversation even when they had Steam downloads running; on the 2860n their downloads run flat out, stats say zero, they don't get throttled and my phone call falls apart.
One other thing I've noticed is that when it switches from WAN1 to WAN2 and vice-versa, the traffic graph sticks at whatever value it was on. So for example, if WAN1 goes down when I was pulling 500kbps, it will show a steady 500kbps line for the next few hours until the line comes back. Clearly it should show zero when not in use.
I've also had some funnies where the web interface was taking 30 seconds to load the page - one element at a time, very, very slowly. And I've also seen the web interface just give me 'skeleton' pages - some of the tables but no data - consistently for a while, but that had sorted itself without a reboot when I looked at it again an hour later.
My setup: 2860n running 3.7.8, VDSL2 on WAN1, failing over to WAN2 and back several times a day. About 30 devices, mostly wired, some wireless connections. IPsec VPN LAN-LAN connection, too. Monitor program connected to telnet port and running 'show status' every 10 seconds.
