Ports 3 and 4 only transmit traffic but not receive

Hi,

 routerboard: yes
             model: CRS109-8G-1S-2HnD
     serial-number: HD60892Q3NR
     firmware-type: ar9344
  factory-firmware: 6.47.10
  current-firmware: 7.14.3
  upgrade-firmware: 7.14.3

I recently converted a CRS router into Bridge mode (connected to my LAN on Ether1). My problem is that only one connected device (Ether2) is able to communicate correctly on the network, get DHCP lease etc, however Ether3 and Ether4 transmit traffic but do not receive traffic.

All other ports have been disabled.

/interface/bridge port print
Flags: I - INACTIVE; H - HW-OFFLOAD
Columns: INTERFACE, BRIDGE, HW, PVID, PRIORITY, PATH-COST, INTERNAL-PATH-COST, HOR
IZON
#    INTERFACE  BRIDGE  HW   PVID  PRIORITY  PATH-COST  IN  HORIZON
;;; defconf
0  H ether2     bridge  yes     1  0x80             10  10  none   
;;; defconf
1  H ether3     bridge  yes     1  0x80             10  10  none   
;;; defconf
2  H ether4     bridge  yes     1  0x80             10  10  none   
;;; defconf
3 IH ether5     bridge  yes     1  0x80             10  10  none   
;;; defconf
4 IH ether6     bridge  yes     1  0x80             10  10  none   
;;; defconf
5 IH ether7     bridge  yes     1  0x80             10  10  none   
;;; defconf
6 IH ether8     bridge  yes     1  0x80             10  10  none   
;;; defconf
7 IH sfp1       bridge  yes     1  0x80             10  10  none   
;;; defconf
8 I  wlan1      bridge          1  0x80             10  10  none   
9  H ether1     bridge  yes     1  0x80             10  10  none



/interface/bridge print
Flags: X - disabled, R - running 
 0 R ;;; defconf
     name="bridge" mtu=auto actual-mtu=1500 l2mtu=1588 arp=enabled 
     arp-timeout=auto mac-address=18:FD:74:B5:8B:98 protocol-mode=rstp 
     fast-forward=no igmp-snooping=no auto-mac=no admin-mac=18:FD:74:B5:8B:98 
     ageing-time=5m priority=0x8000 max-message-age=20s forward-delay=15s 
     transmit-hold-count=6 vlan-filtering=no dhcp-snooping=no 
     port-cost-mode=short

I was hoping somebody could give me an insight as to why that would be happening?

Thanks
Chris