Response from DeepSeek

Some scholars, particularly analyzing oracle bone and bronze script forms of 南, propose that the character originally depicted a suspended object on a frame:

A vertical pole or pillar (representing a sundial, a flagpole, or a central post) With crossbeams or hanging ornaments indicating direction The whole structure facing south, especially in the context of ancient Chinese architecture

Key points of this theory:
Ancient Chinese orientation symbolism The emperor and nobility sat facing south. Buildings, altars, and important structures were aligned north–south, with the main entrance facing south. A pillar or gate facing south would naturally symbolize "south." The character's components The upper part of 南 in bronze script resembles a roof or canopy (冂-like shape), and the lower part resembles a hanging ornament or a post with markings. Some see this as a ceremonial southern gate or a pillar with a directional marker.