@S-A , Thanks for posting this question. Do you receive any specific error messages? Is this issue confined only to a few specific PDFs?
Based on my understanding of your scenario. Just to highlight, OCR skillset is not a free skillset, as outlined in this doc it only supports 20 documents per day.
AttachCognitive Services to a skillset - Azure Cognitive Search | Microsoft Learn
-Image extraction is an Azure AI Search operation that occurs when documents are cracked prior to enrichment. Image extraction is billable on all tiers, except for 20 free daily extractions on the free tier.
Need to use the Microsoft.Skills.Vision.OcrSkill to extract text from image https://docs.microsoft.com/azure/search/cognitive-search-skill-ocr
Extract text from images - Azure AI Search | Microsoft Learn
– See this approach from on SO https://stackoverflow.com/a/73973654 and since the OCR skill calls this same API.
Kindly let us know, I’ll follow up with you further.