unable to establish BGP sessions through different subnets

Hello, I have the following 3 Hosts. Two of the hosts are in the same subnet. The other one is in another /24. I want to do iBGP for EVPN via VXLAN with BGP as control layer. Why is the session for the two hosts in the same subnet established but the server in the other subnet is not reached? Firewall and everything looks ok. Port 149/TCP for BGP is open. Any Idea?

xxx.xxx.249.15 xxx.xxx.249.16 xxx.xxx.254.142

With the following configs: /etc/frr/frr.conf on xxx.xxx.249.15

frr version 4.0
frr defaults traditional
hostname vtep-rr1
no ipv6 forwarding
username cumulus nopassword
!
service integrated-vtysh-config
!
log syslog informational
!
line vty
!
router bgp 65000
  bgp router-id xxx.xxx.249.15
  no bgp default ipv4-unicast
  neighbor fabric peer-group
  neighbor fabric remote-as 65000
  neighbor fabric capability extended-nexthop
  neighbor fabric update-source xxx.xxx.249.15
  !
  neighbor xxx.xxx.249.16 peer-group fabric
  neighbor xxx.xxx.254.142 peer-group fabric
  ! With FRR, use: address-family l2vpn evpn
  address-family l2vpn evpn
   neighbor fabric activate
   advertise-all-vni
  exit-address-family
  !
  exit
!

/etc/frr/frr.conf on xxx.xxx.249.16

frr version 4.0
frr defaults traditional
hostname vtep-rr2
no ipv6 forwarding
username cumulus nopassword
!
service integrated-vtysh-config
!
log syslog informational
!
line vty
!
router bgp 65000
  bgp router-id xxx.xxx.249.16
  no bgp default ipv4-unicast
  neighbor fabric peer-group
  neighbor fabric remote-as 65000
  neighbor fabric capability extended-nexthop
  neighbor fabric update-source xxx.xxx.249.16
  !
  neighbor xxx.xxx.249.15 peer-group fabric
  neighbor xxx.xxx.254.142 peer-group fabric
  ! With FRR, use: address-family l2vpn evpn
  address-family l2vpn evpn
   neighbor fabric activate
   advertise-all-vni
  exit-address-family
  !
  exit
!

/etc/frr/frr.conf on xxx.xxx.254.142

frr version 4.0
frr defaults traditional
hostname vtep-rz
no ipv6 forwarding
username cumulus nopassword
!
service integrated-vtysh-config
!
log syslog informational
!
line vty
!
router bgp 65000
  bgp router-id xxx.xxx.254.142
  no bgp default ipv4-unicast
  neighbor fabric peer-group
  neighbor fabric remote-as 65000
  neighbor fabric capability extended-nexthop
  neighbor fabric update-source xxx.xxx.254.142
  !
  neighbor xxx.xxx.249.15 peer-group fabric
  neighbor xxx.xxx.249.16 peer-group fabric
  ! With FRR, use: address-family l2vpn evpn
  address-family l2vpn evpn
   neighbor fabric activate
   advertise-all-vni
  exit-address-family
  !
  exit
!

xxx.xxx.249.15 # show bgp neighbors

BGP neighbor is xxx.xxx.249.16, remote AS 65000, local AS 65000, internal link
Hostname: vtep-rr2
 Member of peer-group fabric for session parameters
  BGP version 4, remote router ID xxx.xxx.249.16
  BGP state = Established, up for 00:10:47
  Last read 00:00:47, Last write 00:00:47
  Hold time is 180, keepalive interval is 60 seconds
  Neighbor capabilities:
    4 Byte AS: advertised and received
    AddPath:
      L2VPN EVPN: RX advertised L2VPN EVPN and received
    Route refresh: advertised and received(old & new)
    Address Family L2VPN EVPN: advertised and received
    Hostname Capability: advertised (name: vtep-rr1,domain name: n/a) received (name: vtep-rr2,domain name: n/a)
    Graceful Restart Capabilty: advertised and received
      Remote Restart timer is 120 seconds
      Address families by peer:
        none
  Graceful restart informations:
    End-of-RIB send: L2VPN EVPN
    End-of-RIB received: L2VPN EVPN
  Message statistics:
    Inq depth is 0
    Outq depth is 0
                         Sent       Rcvd
    Opens:                  1          1
    Notifications:          0          0
    Updates:                1          1
    Keepalives:            11         11
    Route Refresh:          0          0
    Capability:             0          0
    Total:                 13         13
  Minimum time between advertisement runs is 0 seconds
  Update source is xxx.xxx.249.15

 For address family: L2VPN EVPN
  fabric peer-group member
  Update group 1, subgroup 1
  Packet Queue length 0
  Community attribute sent to this neighbor(all)
  advertise-all-vni
  0 accepted prefixes

  Connections established 1; dropped 0
  Last reset never
Local host: xxx.xxx.249.15, Local port: 43025
Foreign host: xxx.xxx.249.16, Foreign port: 179
Nexthop: xxx.xxx.249.15
Nexthop global: ::
Nexthop local: ::
BGP connection: shared network
BGP Connect Retry Timer in Seconds: 120
Read thread: on  Write thread: on

BGP neighbor is xxx.xxx.254.142, remote AS 65000, local AS 65000, internal link
 Member of peer-group fabric for session parameters
  BGP version 4, remote router ID 0.0.0.0
  BGP state = Active
  Last read 00:10:48, Last write never
  Hold time is 180, keepalive interval is 60 seconds
  Message statistics:
    Inq depth is 0
    Outq depth is 0
                         Sent       Rcvd
    Opens:                  0          0
    Notifications:          0          0
    Updates:                0          0
    Keepalives:             0          0
    Route Refresh:          0          0
    Capability:             0          0
    Total:                  0          0
  Minimum time between advertisement runs is 0 seconds
  Update source is xxx.xxx.249.15

 For address family: L2VPN EVPN
  fabric peer-group member
  Not part of any update group
  Community attribute sent to this neighbor(all)
  advertise-all-vni
  0 accepted prefixes

  Connections established 0; dropped 0
  Last reset never
  Internal BGP neighbor may be up to 3 hops away.
BGP Connect Retry Timer in Seconds: 120
Next connect timer due in 72 seconds
Read thread: off  Write thread: off

FRRouting / frr

unable to establish BGP sessions through different subnets #2276