updating merge customer contacts not working "crmService/FoundationPartiesPersonService "

We recently completed the merge of customer contacts, which processed successfully with a 200 OK status for bulk customer contact records. However, upon reviewing the report, we noticed that some records were not updated as expected. Upon further investigation, we found that the issue was caused by different language characters used in the customer names (e.g., ІНФРАСТРУКТУРИ, СЛУЖБА, etc.).

Could you please provide guidance on how we can ensure the correct processing of customer contacts that contain such characters? Additionally, if there are any recommended solutions or settings we should consider, we would appreciate your insights.