QSFP+ 40G transceiver on 6125XLG down

[fab2]

Hi all,

Is there anything special to 'activate' 40G-ports on 6125XLG ?

I want to connect 6125XLG #1 port FGE2/1/4 to 6125XLG #2 port FGE1/1/4
Ports remain down, whatever the port config is.
The reason is probably : transceivers are not seen.

<PK5-SBY-BS-11>display transceiver interface FortyGigE 2/1/4
The transceiver is absent.
<PK5-SBY-BS-11>
<PK5-SBY-BS-11>display transceiver interface
FortyGigE1/1/1 transceiver information:
The transceiver is absent.
FortyGigE1/1/2 transceiver information:
The transceiver is absent.
FortyGigE1/1/3 transceiver information:
The transceiver is absent.
FortyGigE1/1/4 transceiver information:
The transceiver is absent.
FortyGigE2/1/1 transceiver information:
The transceiver is absent.
FortyGigE2/1/2 transceiver information:
The transceiver is absent.
FortyGigE2/1/3 transceiver information:
The transceiver is absent.
FortyGigE2/1/4 transceiver information:
The transceiver is absent.
...

Same issue with several transceivers, on different ports, on different 6125XLG switch.

If I put the same transceiver (moved from 2/1/4) to one 5900AF-48G-4XG-2QSFP+ , it is reconized right away (even whit default port config + 'shutdown'):
<CIT-PRE-SS-01>display transceiver interface FortyGigE 1/0/53
FortyGigE1/0/53 transceiver information:
  Transceiver Type              : 40G_BASE_SR4_QSFP_PLUS
  Connector Type                : MPO
  Wavelength(nm)                : 850
  Transfer Distance(m)          : 100(OM3)
  Digital Diagnostic Monitoring : YES
  Vendor Name                   : HP
  Ordering Name                 : JG325B
<CIT-PRE-SS-01>

Transceivers are : HPE X140 40G QSFP+ MPO SR4 (JG325B)
They are connected together with : HP 10m PremierFlex OM4 MPO/MPO 8 fibre Multi-Mode Optical Cable (QK729A)
According to QuickSpecs 'HPE 6125XLG Ethernet Blade Switch', QSFP+ 'HPE X140 40G QSFP+ MPO SR4 Transceiver JG325B' are supported.

Attached : picture of the QSFP+ used into the 6125XLG 

Thanks!