Hi @Rahim Molvani,
Thank you very much for sharing the document with me. It has helped me to learn a lot. Also glad to see that your problem is solved.
By the way, since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others.". and according to the scenario introduced here: Answering your own questions on Microsoft Q&A, I would make a brief summary of this thread:
[OneDrive Shared With Me with SharePoint Sever 2019]
Issue Symptom:
The files in the "Shared with Me" folder in OneDrive will only be visible after SharePoint 2019 is crawled.
Current status:
By default, the Shared with Me view is populated once a shared item is crawled and re-indexed through search. This default behavior means that your crawling/indexing schedule may cause some latency between when the item was shared and when it appears in the user's Shared with Me View.
Your users will still be able to open the shared items or folder if they are sent a link (for example, through an email notification), they just won't be able to see the items listed in the Shared with me View until the items have been crawled and indexed.
To eliminate this latency in your SharePoint Server environment, your IT administrator can enable the Recently Shared Items (RSI) cache.
Reference: Enable the Recently Shared Items (RSI) cache to quickly populate the Shared with Me view.
You could click the "Accept Answer" button for this summary to close this thread, and this can make it easier for other community members to see the useful information when reading this thread. Thanks for your understanding!