I enabled mouse-drag-and-drop-region recently and noticed shortly thereafter that it didn't work in org-mode buffers, that is, while I expected to be able to select text and drag it with the mouse elsewhere in the buffer, as normally happens when mouse-drag-and-drop-region is enabled, instead it only sets a mark, as if that setting wasn't enabled. mouse-drag-and-drop-region works fine in buffers with other modes. I also have org-mouse enabled so I decided to temporarily disable it to see if that was related, and indeed, when I don't enable org-mouse in my config, mouse-drag-and-drop-region works fine in org buffers too. This occurs both with the builtin in emacs 26.1 (the version I use) org version (9.1.9), and with the latest org version available from the dedicated org-mode repository[1] (9.2.3 - 20190402 as of this message). Interestingly enough, when I attempt to drag some text with the mouse from a buffer where this works (e.g. *scratch*) to an org-mode buffer, this works fine - it's only dragging text from one part of the org buffer to another that doesn't work. I attach a minimal emacs init file that can used to reproduce the bug[2], as well as a test org file to see the bug in action[3]. Thanks in advance for your understanding.

Emacs version used: 26.1
org mode versions used: 9.1.9 and 9.2.3 - 20190402
Host OSes this was tested on: Linux Mint MATE 18.3 and Windows 7
Expected behavior: while in an org-mode file, be able to drag part of the text with the mouse to elsewhere in the buffer
Actual behavior: sets a mark instead

[1] https://orgmode.org/elpa/
[2] https://gitlab.com/snippets/1843173
[3] https://gitlab.com/snippets/1843174

Emacs  : GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.18.9)
 of 2018-05-29
Package: Org mode version 9.2.3 (9.2.3-elpa @ ~/.emacs.d/elpa/org-20190402/)