Part Padstack on wrong layer / bonding / Flex zones

Cadence 17.2.

I'm using a library BB-via defined with only one layer (Layer = BONDS, just below TOP) and this is a connect pin of a part.

NB : I'm using this trick 'cos I can't use the Allegro Bonding feature since it is limited to 100 bonds with the std Allegro PCB editor package.

type: Blind/Buried Via
Hole data size = 0.0000

Design layer pads

Layer: BEGIN LAYER = DEFAULT INTERNAL  = END LAYER  = ADJACENT LAYER  = None

Layer: BONDS

In the package, info on pin is correctly defined on BONDS layer.

info on pin:

pin number: 120

Padstack name:   BP_SQR_0-085

Usage:           Bbvia  

padstack defined only on BONDS

When I put the part in the PCB design, the pad is swapped onto the BOTTOM layer ????

info on pin:

  pin number: U1.120

  pin name:     BANDGAP

  pinuse:       UNSPEC

  Zone name:    PCB_P1

  location-xy:  (64.5250 43.1875) 

  Part of net:       N473817_HALF-SIDE0_ADC

  Number of connections: 0

  Reference padstack name:   BP_SQR_0-085

  Usage:           Bbvia  

  padstack defined only on BOTTOM

  pin is EXPLODED from symbol

  padstack rotation:   270.000  degrees

  Attached text:

   class      = PACKAGE GEOMETRY

   subclass   = PIN_NUMBER

   value      = 120

Properties attached to symbol pin

    CLIP_DRAWING      = CLIP_1

When I edit this padstack design, the padstack is correctly defined on BONDS layer, as in the library padstack put in the part.

=> there is clearly an issue there.

I did several trials withiout any success:

- db check

- delete part, repackaging, replace part

- update symbol, with and w/o 'Update symbol padstacks from library'

NB : I'm using also the Flex zones, but BONDS layer is enabled on the zone I place this part.