Currently a Nozzle in Nozzle Manager is defined by the NUMBER field. When using PlantSight/OPPID/OPM, the Number needs to be defined as a Number - Not N1 or M1 (Nozzle or Manhole). Tagging of a nozzle is generally defined as EQP_NO-DEVICE_TYPE_CODE & NUMBER, where DEVICE_TYPE_CODE could be N (Nozzle) or M (Manhole), or other.

eg. EQP_NO-M1, EQP_NO-N1, etc

When placing in OPPID, syncing to PlantSight (where the NAME property for NOZZLE is defined and is acceptable as EQP_NO-DEVICE_TYPE_CODE & NUMBER), and then retrieving the nozzle information in OPM, Nozzle Manager won't allow duplicate numbers (Nozzle Manager defines Uniqueness purely based on property NUMBER - this is HARDCODED and not modifiable in schemas).
If DEVICE_TYPE_CODE can be included in determining Uniqueness, then this will help resolve this issue.