Custom properties variableNames and variableValues are cleared when more than one layer custom variable exist

[DelazJ]

What is the bug or the crash?

Layer properties --> Information tab has a custom properties section.
Among the predefined custom properties, we have variableNames and variableValues. Given their pluralized name, I assume they are supposed to return a list of the custom variables name and value. No idea for the expected formatting.

The issue here is that when you have ONE custom variable, it is displayed correctly but when they are more than one, the fields are turned empty

Steps to reproduce the issue

Enregistrement.de.l.ecran.2024-05-03.a.16.31.03.mov

Versions

Tested on 3.36.0

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response