Not able to enable ports on Accton switch

See attached topology graph: if we disable and reenable any port connecting to switch 225 from ONOS, the corresponding port on switch 225 remains disabled and won't come up unless we reset the port speed.

Example: if we disable and enable port 51 on switch 204 by

onos> portstate of:0000000000000204 51 disable
onos> portstate of:0000000000000204 51 enable

The link goes down and never comes up because port 31 on the other end of this link, i.e. switch 225. stays in disabled state.

onos> ports of:0000000000000225 | grep 31
  port=31, state=disabled, type=fiber, speed=40000 , adminState=enabled, portMac=cc:37:ab:7c:bc:7f, portName=port31

The port on switch 204 side is enabled correctly.

We can fix the problem by running "client_drivshell port 31 sp=40000" on the switch. However every port on the switch should be already 40G by default.
Before re-setting the port speed

Feb  4 23:18:43 localhost OFDPA[7927]: SDK:       xe30( 31)  down   40G  FD   SW  No   Forward         Untag    F    CR4  9412

After re-setting the port speed

Feb  4 23:18:57 localhost OFDPA[7927]: SDK:       xe30( 31)  up     40G  FD   SW  No   Forward          None    F    CR4  9412

More details:
ONOS version: 1.15

switch 225:
Vendor : Accton Corp.
H/W Version : x86-64-accton-as6712-32x-r0
S/W Version : ofdpa 1.1.7.2-premium+accton1.0-1

switch 204:
Vendor : Broadcom Ltd.
H/W Version : Accton AS5912-54x
S/W Version : OF-DPA Premium 1.1.5.6