I have a similar problem.
I have 2 DSL modems and when I disable the second gateway in netbalancer, internet works.
If I disable the failover monitor I still get connections and bits are increasing.
Just replace IP1 / IP2 / IP3 with your ip to check that connection is alive…
The arguments in oder (the same on the web page net balancer)
MODE (LBFO for me : balancing and failover)
ICMPCheck (activate the icmp check)
ProbesDOWN (Number of probes before marking DOWN)
ProbesUP (Number of probes before marking UP)
Timeout (Reply timeout (seconds)
Pause (Pause before starting a new cycle (seconds)
PPPDRestart (Immediately restart PPPoE and 3G Mobile (Yes/no)
IP1 ( Failover IP Addresses 1)
IP2 ( Failover IP Addresses 2)
IP3 ( Failover IP Addresses 3)
Hope it can help somebody else ! And if you have the fix, tell me ! 🙂