Fuzzy bold fonts when `QT_QPA_PLATFORMTHEME=qt5ct`

[loathingKernel]

When using the above environment variable, the bold text (either set by Qt Designer or <b></b> tags) appears fuzzy.

Notice the QRadioButton labels on the left and the rightmost labels.

In contrast with QT_QPA_PLATFORMTHEME unset, the bold text appears correct.

This is with the default qt5ct configuration with DejaVu Sans font size 9

The same behavior is present in Qt6 with qt6ct. qt5ct version is 1.7, and qt6ct is 0.8 from the Arch repositories.

I have tested this with a few applications, some of my own so I can provide any more information if required.