Why no spacing between frame and text?

In my document, there are is no spacing between figures/frames and text. This happens even though all of the paragraph styles have spacing above them and there is no manual formatting.

What could prevent the paragraph styles from being applied?

Right click on the frame → Properties → Wrap tab: there you can set the space around the frame. That spacing can be set in a frame style too, but you need to be aware of Bug 32485 and reapply the frame style when you insert a caption.

To be clear, are you saying that the figure/frame properties override paragraph styles?

These are two different things. Paragraph properties are used to lay out the main text flow. Frames do not participate in text flow. Consider they are “exceptions” to it. They can be superimposed to text (wrap Through) or punch a hole of various shape in the page (all other wrap modes). The metric properties in Wrap tab allow you to control the size of this “hole” while the Type tab sets its position.

In a sense, it “overrides” because it changes the area available for setting out text, the same way page margins define the printable area.