x sfp 1.9.0: ip route flush every 10-12s

Hi,

the other day I configured my edgerouter x sfp firmware 1.9.0 to send logs to a remote server. I then saw that the router was issuing this command every 11s:

root : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/sbin/ip route flush table 201

I have load balance configured in failover mode:

Group WLB
  interface   : pppoe0
  carrier     : up
  status      : active
  gateway     : pppoe0
  route table : 202
  weight      : 100%
  flows
      WAN Out : 22515
      WAN In  : 0
    Local Out : 420

  interface   : eth0
  carrier     : up
  status      : failover
  gateway     : 100.64.32.1
  route table : 201
  weight      : 0%
  flows
      WAN Out : 0
      WAN In  : 0
    Local Out : 0

And that 201 table is for the backup link:

$ ip route list table 201
default via 100.64.32.1 dev eth0 
blackhole default  metric 256 

Interestingly enough, I just noticed that the backup link is actually down:

$ show load-balance watchdog 
Group WLB
  eth0
  status: Waiting on recovery (0/3)
  failover-only mode
  pings: 3
  fails: 3
  run fails: 3/3
  route drops: 1
  ping gateway: ping.ubnt.com - DOWN
  last route drop   : Sat Sep  3 08:21:46 2016

  pppoe0
  status: Running 
  pings: 10697
  fails: 11
  run fails: 0/3
  route drops: 0
  ping gateway: ping.ubnt.com - REACHABLE

This sudo log doesn't show locally on the router, so I can't tell when it started happening. Could very well be related to the backup link being down, which I will investigate in a moment.