I’ve disabled that route, I’ll paste here my /ipv6/route/print:
[admin@MikroTik] > /ipv6/route/print
Flags: D - DYNAMIC; X - DISABLED, I - INACTIVE, A - ACTIVE; c - CONNECT, s - STATIC, d - DHCP, v - VPN
Columns: DST-ADDRESS, GATEWAY, ROUTING-TABLE, DISTANCE
# DST-ADDRESS GATEWAY ROUTING-TABLE DISTANCE
0 Xs ::/0 fe80::1 main 1
DAv ::/0 pppoe-out1 main 1
DAd 2804:35e0:11aa:cb00::/56 main 1
DAc 2804:35e0:11aa:cb00::/64 bridge main 0
DAc fe80::/64 bridge main 0
DAc fe80::/64 wireguard1 main 0
DAc fe80::/64 ether1 main 0
DAc fe80::/64 pppoe-out1 main 0
DAc ::1/128 lo main 0
If you need any other configuration, let me know.
I did a downgrade to 7.18.2 but no changes in this matter. After checking some other posts and digging the internet, I’ve did some changes, here is my updated /ipv6/export:
# 2025-05-16 09:08:00 by RouterOS 7.18.2
# software id = IEVE-CLRM
#
# model = RB760iGS
# serial number = HDA08D5JYR2
/ipv6 address
add address=::1 from-pool=pool6 interface=bridge
/ipv6 dhcp-client
add interface=pppoe-out1 pool-name=pool6 request=address,prefix
/ipv6 dhcp-server
add address-pool=pool disabled=yes interface=bridge name=server1 prefix-pool=pool use-reconfigure=yes
/ipv6 firewall address-list
add address=::/128 comment="defconf: unspecified address" list=bad_ipv6
add address=::1/128 comment="defconf: lo" list=bad_ipv6
add address=fec0::/10 comment="defconf: site-local" list=bad_ipv6
add address=::ffff:0.0.0.0/96 comment="defconf: ipv4-mapped" list=bad_ipv6
add address=::/96 comment="defconf: ipv4 compat" list=bad_ipv6
add address=100::/64 comment="defconf: discard only " list=bad_ipv6
add address=2001:db8::/32 comment="defconf: documentation" list=bad_ipv6
add address=2001:10::/28 comment="defconf: ORCHID" list=bad_ipv6
add address=3ffe::/16 comment="defconf: 6bone" list=bad_ipv6
/ipv6 firewall filter
add action=accept chain=input comment="defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=fasttrack-connection chain=forward comment="defconf: fasttrack6" connection-state=established,related
add action=accept chain=forward comment="defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=accept chain=forward dst-address=2804:35e0:11b0:4e00:fd71:fb75:ed20:b38d/128 dst-port=25565 in-interface=pppoe-out1 \
protocol=tcp
add action=accept chain=forward dst-address=2804:35e0:11b0:4e00:fd71:fb75:ed20:b38d/128 dst-port=25566 in-interface=pppoe-out1 \
protocol=tcp
add action=accept chain=forward dst-address=2804:35e0:11b0:4e00:fd71:fb75:ed20:b38d/128 dst-port=24454 in-interface=pppoe-out1 \
protocol=udp
add action=accept chain=forward dst-address=2804:35e0:100f:0:2249:e830:0:9/128 dst-port=13231 in-interface=pppoe-out1 protocol=\
tcp
add action=accept chain=forward dst-address=2804:35e0:100f:0:2249:e830:0:9/128 dst-port=13231 in-interface=pppoe-out1 protocol=\
udp
add action=drop chain=input comment="defconf: drop invalid" connection-state=invalid
add action=accept chain=input comment="defconf: accept ICMPv6" protocol=icmpv6
add action=accept chain=input comment="defconf: accept UDP traceroute" port=33434-33534 protocol=udp
add action=accept chain=input comment="defconf: accept DHCPv6-Client prefix delegation." dst-port=546 protocol=udp src-address=\
fe80::/10
add action=accept chain=input comment="defconf: accept IKE" dst-port=500,4500 protocol=udp
add action=accept chain=input comment="defconf: accept ipsec AH" protocol=ipsec-ah
add action=accept chain=input comment="defconf: accept ipsec ESP" protocol=ipsec-esp
add action=accept chain=input comment="defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
add action=drop chain=input comment="defconf: drop everything else not coming from LAN" in-interface-list=!LAN
add action=drop chain=forward comment="defconf: drop invalid" connection-state=invalid
add action=drop chain=forward comment="defconf: drop packets with bad src ipv6" src-address-list=bad_ipv6
add action=drop chain=forward comment="defconf: drop packets with bad dst ipv6" dst-address-list=bad_ipv6
add action=drop chain=forward comment="defconf: rfc4890 drop hop-limit=1" hop-limit=equal:1 protocol=icmpv6
add action=accept chain=forward comment="defconf: accept ICMPv6" protocol=icmpv6
add action=accept chain=forward comment="defconf: accept HIP" protocol=139
add action=accept chain=forward comment="defconf: accept IKE" dst-port=500,4500 protocol=udp
add action=accept chain=forward comment="defconf: accept ipsec AH" protocol=ipsec-ah
add action=accept chain=forward comment="defconf: accept ipsec ESP" protocol=ipsec-esp
add action=accept chain=forward comment="defconf: accept all that matches ipsec policy" ipsec-policy=in,ipsec
/ipv6 nd
set [ find default=yes ] advertise-mac-address=no dns=2001:4860:4860::8888,2606:4700:4700::1111 interface=bridge \
managed-address-configuration=yes other-configuration=yes
add advertise-dns=no advertise-mac-address=no interface=pppoe-out1 ra-lifetime=none
/ipv6 route
add disabled=yes distance=1 dst-address=::/0 gateway=fe80::1 routing-table=main scope=30 suppress-hw-offload=no target-scope=10
/ipv6 settings
set accept-router-advertisements=yes
---------------- EDIT ---------------
After reading this specific post http://forum.mikrotik.com/t/ipv6-trouble/174887/1 and adding a MTU of 1480 in my ND, everything is working as expected.
[admin@MikroTik] /ipv6/nd> print
Flags: X - disabled, I - invalid; * - default
0 * interface=bridge ra-interval=3m20s-10m ra-delay=3s mtu=1480 reachable-time=unspecified retransmit-interval=unspecified
ra-lifetime=30m ra-preference=medium hop-limit=unspecified advertise-mac-address=no advertise-dns=yes
managed-address-configuration=yes other-configuration=yes dns=2001:4860:4860::8888,2606:4700:4700::1111
1 interface=pppoe-out1 ra-interval=3m20s-10m ra-delay=3s mtu=1480 reachable-time=unspecified retransmit-interval=unspecified
ra-lifetime=none ra-preference=medium hop-limit=unspecified advertise-mac-address=no advertise-dns=no
managed-address-configuration=no other-configuration=no