403 In Azure OpenAI when using vector embedding in Azure AI Search Index

Question

I have an AI Search and Azure OpenAI deployed in private mode, meaning access is only allowed through private endpoints. I also configured Azure AI Search with a shared private endpoint to my Azure OpenAI. Additionally, I deployed a WebApp in Azure App Service that provides a chat web interface, and this WebApp is also deployed in private mode. The environment works perfectly, and communication between different components is private.

The issue arises when I try to use the vectorization endpoint; I encounter a 403 Forbidden error when AI Search tries to access Azure OpenAI. I noticed in the Azure OpenAI logs (in the Log Analytics Workspace) that AI Search is trying to access Azure OpenAI via a public IP (20.105.245.*).
When I added this public IP to the Azure OpenAI firewall, the vector embedding in AI Search works

My concerns are as follows:

1. Why does the vector embedding use a public IP instead of a private endpoint, while all other functionalities work fine and use private endpoints?
2. This public IP is different from the public IP attached to my AI Search instance and may be shared with other AI Search clients.

Has anyone else experienced a similar issue, or does anyone have insights into potential causes or solutions? Any help or guidance on this matter would be greatly appreciated.

Thank you!