Problem with image defined as variable when closing / opening project

[simogeo]

Describe the bug
From Map Composer (gestionnaire de mise en page), Image is not displayed when defined from project variable and opening again a project

How to Reproduce

1. Create a project
2. Define a variable like `project_layout_logo' and set the path to image
3. Create a new Map composer layout.
4. Add an image specifying the variable
5. Save your project
6. Close your project
7. Open it again and go to map print layout - Image is missing, replaced by Red cross. You need to specify again the variable.

QGIS and OS versions

Version de QGIS | 3.8.1-Zanzibar | Révision du code | dcd95cc
Compilé avec Qt | 5.9.5 | Utilisant Qt | 5.9.5
Compilé avec GDAL/OGR | 2.2.3 | Utilisé avec GDAL/OGR | 2.2.3
Compilé avec GEOS | 3.6.2-CAPI-1.10.2 | Utilisé avec GEOS | 3.6.2-CAPI-1.10.2 4d2925d6
Version du client PostgreSQL | 10.9 (Ubuntu 10.9-0ubuntu0.18.04.1) | Version de SpatiaLite | 4.3.0a
Version de QWT | 6.1.3 | Version de QScintilla2 | 2.10.2
Version de PROJ.4 : | 493
OS Version | Ubuntu 18.04.3 LTS |  

[roya0045]

So the main issue is that the variable doesn't remain in the project, rather than an issue with the image itself?

[simogeo]

The variable remains in the project but is not selected by default. Have to select it again each time I open the project

Clicking the yellow dropdown image button (in object properties). I can see Variable is selected instead of the right one !

☑ Variable
☐ Current : @project_layout_logo

[nyalldawson]

Confirmed