ID 495487 - Importing Selected Layers from a Session file imports all Layers

Problem summary
Importing Selected Layers from a Session file imports all Layers 

Customer reported version
Mari 4.6v3

Customer reported platform
RHEL7

Steps to reproduce

1) Open an Example Project

2) Create a new Layer in the Diffuse_Head_Geo Channel, then rename it 'Test Layer'

3) With the new Test Layer selected, open the Export Session dialog by clicking File > Session > Export Session

4) Choose a suitable export path and click OK

5) Delete the Diffuse_Head_Geo Channel

6) Open the Import Channels dialog by clicking File > Session > Import Channels

7) Select the exported .msf file to import

8) Drag the Diffuse_Head_Geo Channel in the left pane onto the Head_Geo Object in the right pane

9) In the Import dropdown menu, select Selected Layers

10) Click Import, then close the dialog and check the imported Diffuse_Head_Geo Channel's Layerstack

Expected behaviour
Only the Test Layer that was selected when exporting the Session should be imported  

Actual behaviour
All of the Diffuse_Head_Geo Channel's original Layers are imported

Workaround
Unknown.

Reproduced by support
This bug has been reproduced in:
Mari 4.7v4 - Windows 10 - CentOS 7.9
Mari 4.6v1 - Windows 10
Mari 4.5v2 - Windows 10 - CentOS 7.9 - regression

Unable to reproduce bug in:
Mari 4.2v2 - Windows 10 - CentOS 7.9

Earliest version tested
Mari 4.2v2 - This issue doesn't appear in this version and has regressed