Help! MWAN3 can't detect IPv6 anymore

Hi all,

I hope somebody can help me out. This used to work weeks ago but now whatever I do, MWAN3 is saying that IPv6 is down even though it is not.

Below are the logs generated by MWAN3

Mon Mar 24 20:09:00 2025 user.info mwan3track[19792]: Detect ifup event on interface wan6 (eth1)
Mon Mar 24 20:09:00 2025 user.notice mwan3track[19792]: Interface wan6 (eth1) is online
Mon Mar 24 20:09:04 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1001" on interface wan6 (eth1). Current score: 10
Mon Mar 24 20:09:08 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1111" on interface wan6 (eth1). Current score: 10
Mon Mar 24 20:09:12 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccd::2" on interface wan6 (eth1). Current score: 10
Mon Mar 24 20:09:16 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccc::2" on interface wan6 (eth1). Current score: 10
Mon Mar 24 20:09:16 2025 user.notice mwan3track[19792]: Interface wan6 (eth1) is disconnecting
Mon Mar 24 20:09:25 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1001" on interface wan6 (eth1). Current score: 9
Mon Mar 24 20:09:29 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1111" on interface wan6 (eth1). Current score: 9
Mon Mar 24 20:09:33 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccd::2" on interface wan6 (eth1). Current score: 9
Mon Mar 24 20:09:37 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccc::2" on interface wan6 (eth1). Current score: 9
Mon Mar 24 20:09:46 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1001" on interface wan6 (eth1). Current score: 8
Mon Mar 24 20:09:50 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1111" on interface wan6 (eth1). Current score: 8
Mon Mar 24 20:09:54 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccd::2" on interface wan6 (eth1). Current score: 8
Mon Mar 24 20:09:58 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccc::2" on interface wan6 (eth1). Current score: 8
Mon Mar 24 20:10:07 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1001" on interface wan6 (eth1). Current score: 7
Mon Mar 24 20:10:11 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1111" on interface wan6 (eth1). Current score: 7
Mon Mar 24 20:10:15 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccd::2" on interface wan6 (eth1). Current score: 7
Mon Mar 24 20:10:19 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccc::2" on interface wan6 (eth1). Current score: 7
Mon Mar 24 20:10:28 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1001" on interface wan6 (eth1). Current score: 6
Mon Mar 24 20:10:32 2025 user.info mwan3track[19792]: Check (ping) failed for target "2606:4700:4700::1111" on interface wan6 (eth1). Current score: 6
Mon Mar 24 20:10:36 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccd::2" on interface wan6 (eth1). Current score: 6
Mon Mar 24 20:10:40 2025 user.info mwan3track[19792]: Check (ping) failed for target "2620:0:ccc::2" on interface wan6 (eth1). Current score: 6
Mon Mar 24 20:10:40 2025 user.notice mwan3track[19792]: Interface wan6 (eth1) is offline

The weird part is, I can ping those IP through the wan6 (eth1) interface.

# ping -c 4  2606:4700:4700::1111
PING 2606:4700:4700::1111 (2606:4700:4700::1111): 56 data bytes
64 bytes from 2606:4700:4700::1111: seq=0 ttl=57 time=22.793 ms
64 bytes from 2606:4700:4700::1111: seq=1 ttl=57 time=50.511 ms
64 bytes from 2606:4700:4700::1111: seq=2 ttl=57 time=33.141 ms
64 bytes from 2606:4700:4700::1111: seq=3 ttl=57 time=45.823 ms

--- 2606:4700:4700::1111 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 22.793/38.067/50.511 ms
ping -c 4 -6 -I eth1 2606:4700:4700::1111
PING 2606:4700:4700::1111 (2606:4700:4700::1111): 56 data bytes
64 bytes from 2606:4700:4700::1111: seq=0 ttl=57 time=22.713 ms
64 bytes from 2606:4700:4700::1111: seq=1 ttl=57 time=70.744 ms
64 bytes from 2606:4700:4700::1111: seq=2 ttl=57 time=61.073 ms
64 bytes from 2606:4700:4700::1111: seq=3 ttl=57 time=58.956 ms

--- 2606:4700:4700::1111 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 22.713/53.371/70.744 ms
# ping -c 4 -6 -I eth1 google.com
PING google.com (2404:6800:4005:822::200e): 56 data bytes
64 bytes from 2404:6800:4005:822::200e: seq=0 ttl=118 time=82.364 ms
64 bytes from 2404:6800:4005:822::200e: seq=1 ttl=118 time=84.204 ms
64 bytes from 2404:6800:4005:822::200e: seq=2 ttl=118 time=85.056 ms
64 bytes from 2404:6800:4005:822::200e: seq=3 ttl=118 time=86.496 ms

--- google.com ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 82.364/84.530/86.496 ms

So scratching my head why MWAN3 saying it can't ping the IPv6 addresses and detecting it as down.

My setup is failover and below are the Interface status according to MWAN3

Interface status:
 interface wan is online and tracking is active (online 39h:21m:26s, uptime 39h:21m:28s)
 interface wan6 is offline and tracking is active
 interface wanb is online and tracking is active (online 86h:58m:00s, uptime 86h:59m:21s)
 interface wanb6 is unknown and tracking is down (31)
 interface nordlynx is online and tracking is active (online 00h:26m:51s, uptime 00h:26m:54s)

Does anybody really not know how to fix this issue? I've tried everything I can think of but can't get MWAN3 to detect the WAN6 even though the connection is working.