SharePoint 2019 only in combination with Internet Explorer has issues with switching from Modern Experience to Classic Experience and back to Modern Experience.
When you do this actions the icons above the document library aren't correct.

*English follows Japanese

■Title(件名)：
ファイルの言語判定について
Determination of file language

■Description(内容):
ドキュメント ライブラリにアップロードしたファイルについて、日本語のファイルか、日本語以外の言語のファイルかの言語判定が、曖昧な動作をしているように思える。同じ操作で同じ内容で作成したファイルでも言語判定がわかれることがあるので、動作の精度を上げて欲しいのと、判定の基準のようなものがあれば公開して欲しい。

When files are uploaded to document libraries, files which are in Japanese are incorrectly identified as being in other languages, with no clear reason. There are cases where files with the same content created in the same way are determined to be in different languages, so please improve this function, and publish information about how the determination of file languages functions.

The form that we see in any document library in a modern view should be editable i.e., user should be able to add web parts in that page including images, headings,etc.

Allow the ability to create a planner task when a file is selected so that users can easily create and assign tasks from Document library view. It would be a really helpful way to notify the team about an document and create,assign a planner task from it.

When a file is uploaded to a document library with a client using the resolution 1366x768 the toolbar is not fully responsive and the most right button disappears until the file is completely uploaded.

When a site visitor shares a folder to a non-member of a site, it would be very helpful if the Permission Levels are available for selection. This way, when the site owner receives the request for access, he/she will see right away the type of access needed. Instead of having to reach out to the requestor to clarify.

Thank you.

In a document library, the information pane or details pane has, under the More details, a Type, Modified and Path attribute value displayed for an object, file or folder.
These attributes, especially the Path attribute value, need to be moved to the top of the pane before the Activity list. Trying to use the Path 'Copy' feature is difficult when you have to scroll to the bottom of an Activity list that is busy and very long!

Please! Bring back the folder "Change New Button Order" option in Modern UI. This option can display only a subset of content types attached to a library in a specific folder. This makes life easier for end user. Also the option enables you to set a default content type for all new content in a folder.

When sharing files and folders SharePoint Online/OneDrive for Business should use a Guid based URL. I have learned that changing a user's UPN or even the name of a folder or file can break those links due to the URL format.

Box uses a unique folder or file id for all items and no matter if I move that file/folder or change the user's username the link does not break.

In SharePoint 2016 & SPO (Perhaps also 2019) there is a New Folder Creation Bug - wherein Title is not automatically set to the Name value during creation.

However, if you rename the field, even without changing the value, and click "Save", it will properly set the Title.

This has been confirmed in SP 2016 and SP Online.

Document Libraries do not show the classification of PDF documents which are protected through Microsoft Information Protection. This works for Office documents, but most of our customers have many PDF documents that need protection. Currently, they cannot trust what they see in SharePoint as only Office files show their classification.

We have students create subsites and share document libraries to external users. We would like to hide the student emails after they share the subsite with an external email by either moving the user email address to the BCC line or selecting a custom FROM address/user.

I would like to be able to open various files directly in the desktop application, not just office documents.
Currently, you have to download it to open it in a desktop application, so you have to download it, edit it, and then upload it.
BOX seems to be able to do that.

It would be great if we could give users the access permission by each group folder of the different hierarchy level in the SharePoint document library.

It would be great if the grouping function of the view could allow us to group the view with three or more levels in the document library. Because the current grouping function can only group by the second level.

There is a link to the item in the body of the notification email, but the entire document library is displayed and it is difficult to see which item was added. I would like improvements so that I can access the items directly.
 
通知のメールの本文中に該当のアイテムのアクセスできるリンクがあるが、ドキュメン トライブラリ全体が表示され、どのアイテムが追加されたか分かりにくい。アイテムに直接アクセスができるように改善を希望します。