Filter Photos missing from folder reports photos missing, but they are not m - Lightroom Classic 9.1

[Arnold-Norway]

Lightroom Classic 9.1 says 4332 photos are missing from folder 2019, but they are all in the catalog. I can right click and choose Go To Folder in Library, and Lightroom opens the folder, and shows the photo every time. 
Optimize catalog does not change number of missing photos. The file names have not been changed. I am conserned  that removing the missing photos will remove the existing photos - as they are the same, so how can we solve this issue?
I really wonder how this could happen.

{Thread renamed by moderator}

[Sahil.Chawla]

Hi Arnold,

That sounds strange, could you please have a look at a similar conversation here and let us know if it helps?
https://community.adobe.com/t5/lightroom-classic/missing-photos-but-not-missing/m-p/9328140#M67467

Regards,
Sahil

[Arnold-Norway]

Thanks for your reply, Sahil. 
The conversation in the link does not give me any additional knowledge.
The filter in the Catalog panel show 4332 photos missing from the folder. When showing in Library Grid View, there ar no exclamation marks. The catalog link si correct, as I can use both the Goto Folder in Library and Show in Finder to show every one of the photos.
I have searcher for file name in Library filter All Photographs marked, to look for duplicate file names, but no - there is only one of each.

I agree - this is very strange. Because the catalog link is correct, I am afraid to remove the missing photos, because that may remove the existing photos, as they are the same.
I consider my selv as an advanced user, so know how to find and locate missing photos and folders, but I consider that is not the case here.

[JohanElzenga · Accepted solution]

Run the 'Library - Find All Missing Photos' menu again. This collection is not a smart collection. It does not automatically update itself when the photos are no longer missing, nor does it automatically get removed from the panel.

[Arnold-Norway]

Thank you, JohanElzenga
You are right, I can run a search from the menu, and the result is presented in the Catalog panel. 
Somehow there must be som internal housekeeping in the catalog, because yesterday the Photos missing from the folder was correct, when Lightroom was started.

Case is solved now - thanks again.