Hello,
Since I finally found the solution, I will share it here in case other people meet the same problem.
Some entries were indeed missing in this customizing :
Spro > CRM > UI Framework > Technical role definition > Define navigation bar profile > Select Z business role affected > Define Generic Outbound plug Mappings.
Here, verify or add if missing the following entries :
Object type = PRD_MATSRV
Target ID = MD-PR01-OV
Highlight = MD-MAT-SR
Regards,
Guillaume