Unable to dock notebooks to the canvas side of the dock

Steps to reproduce:

• open Inkscape
• open two dialogs
• dock both of them to the Right side of the canvas
• try to dock the second dialog next to canvas (Left) so you have two tabs(notebooks) next to each other

2021-05-12_15-10-02

What happened?

• nothing

What should have happened?

• dock to the left

Version Info:

Inkscape 1.1-rc (52f87abb86, 2021-05-02)

GLib version:     2.68.1
GTK version:      3.24.29
glibmm version:   2.66.0
gtkmm version:    3.24.3
libxml2 version:  2.9.10
libxslt version:  1.1.34
Cairo version:    1.17.4
Pango version:    1.48.4
HarfBuzz version: 2.8.0
Poppler version:  20.12.1

OS version:       Windows 10 2009