This. DOF can be VERY narrow in macro. It can be as narrow as a few mm. I've seen pics taken with good macro lenses with very narrow DOFs. Saw one pic of an ant. The thorax was in focus and the head was not.
Edge and corner sharpness are rarely as good as centre sharpness. It’s not high-performance macro lense. It’s just a phone camera with noticeable edge and corner softening.
The macro mode is also using the ultra wide lens, which close up becomes closer to fish eye perspective.
That’s why it get blurry around the subject in every direction.