TailReader of Drag window wrong

[tualatin]

Expected behavior and actual behavior

Current behavior is, that the TailReader does not work, when it comes from a Drag window. The log collection is empty, when Drag window is create.
The TailReader of every Drag window should work, log collection should copy to new Drag window.

Steps to reproduce the problem

Start TailReader, create a second TabItem, select the item with the running TailReader. Drag this item out of current window, so that a new Drag window is create. The new window is empty, TailReader does not show new lines. Current collection is empty.

Specifications like the version of the project, operating system, or hardware.