Data-defined expression for labels "tab distance" doesn't seem to work

[DelazJ]

What is the bug or the crash?

1. In a vector layer label properties, provide a label containing tab character(s)
2. In "formatting" tab, Set "tab distance" to some value and apply (to check everything works as expected)
3. Now, try to override using the data-defined button on the right. Provide a different number or an array of numeric values, and OK -> apply. Nothing changes in the map canvas.

Steps to reproduce the issue

Read above

Versions

Tested with master 3.41 98c5bf8 on windows 10

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