All products have the same mapping numbers after Auto-Mapping Tool is applied

**Description:**
When Auto-Mapping Tool (Discard, Keep or Alter) is applied, all products in the reaction from mapping2.rxn file have the same numbers.

**Steps to reproduce:**
1. Open the file _mapping2.rxn_
2. Click the Reaction Auto-Mapping Tool.
3. Choose mode Discard, Keep or Alter.
3. Click OK button.

**Actual result:**
All products have the same mapping numbers.

**Expected result**
Each product should have its unique mapping number.