Ok, I've made some digging on Home Assistant GH and found out it's not a bug but a feature, but they just haven't put any info about the change to their documentation:
https://github.com/home-assistant/core/issues/62703
Long story short, to use the notation “[Sketch name] [Node id] [Child id]”, there should be no sensor description in presentation().
This is supposed to work with “[Child description]” notation:
present(NOTIFY_SENSOR_ID, S_INFO, "Child description");
And this with “[Sketch name] [Node id] [Child id]” notation:
present(NOTIFY_SENSOR_ID, S_INFO);