Source editor text rendering/scaling wrong (ugly)

The main source editor text rendering has something wrong with the scaling/quality and in a larger text mass becomes "ugly" enough for me to stop using this version altogether.

Problem is evident in both X11 and Wayland.

It appears to be scaling related.

This problem occurred since 4.11.0 only. Can downgrade to 4.10.2 and all is fine again.

Providing attachments from both versions with text snippet (both has set QtCreator scaling to 100%, e.g. no scaling changes).