Text drag-and-drop not working

I'm experiencing what appears to be a bug in InDesign for Windows (InDesign 21.4.1).

After updating to InDesign 21.x, I can no longer drag selected text to another position.

Here's what I've confirmed:

• Object frames can be dragged normally.

• Only text drag-and-drop is affected.

• This happens in multiple documents, including newly created ones.

• Resetting Preferences did not fix the issue.

• The most interesting part is that, on Master Pages, drag-and-drop works on the right-hand page, but does not work on the left-hand page.

• Another Japanese user reported exactly the same issue on the Adobe Community forum several months ago, and the discussion remains unresolved.

Is this a known bug? Can anyone reproduce this issue on Windows?

The issue started after updating to InDesign 21.x. After downgrading to InDesign 19.x, text drag-and-drop works normally again.

I also contacted Adobe Support by phone, but the issue could not be resolved.

*Here's the Japanese thread describing the same issue.