Searchbox missing for external users in document library

Question

When I share a folder with multiple subfolders (read access) in a document library in Sharepoint online with an external user. Is it possible for an external users to search in the document library for the documents they have access to? If not, is it possible to turn it on?

I have a customer saying that he could search for documents a few days ago and has been able to do that for a long time, but not any more since the searchbox has gone missing. When I test, I cannot see the Search either as an external user, nor can I see any settings related to it.:

Answer 1

The global search box in modern SharePoint is hidden by default for external users, and there is no setting to turn it on currently, even if they are still able to use search function in this library.

Here are a few workarounds:

1. Give the external users (at least View Only) permission at site level, which will give them access to the old version of search box in this site.
2. Switch the library to classic experience. The classic search box is still available for external users when they have access on library level. No further permission is needed in other locations.

Answer 2

@Chelsea_MSFTs answer really helped, but what really was the difference was how you invite people. If I share a folder with a link to a external user. They don't see the Searchbox. If I give the external user direct access, they do see the seraachbox. (No matter giving permissions at Site, library or file level)