Smart move. A controlled test with known content strips away all the variables. We'll know exactly what text went in, so anything weird that comes out is the system doing it, not your old content. Good troubleshooting instinct.

Here's clean filler with a clear heading hierarchy. It's dummy copy, so don't worry about the substance. What matters is the structure: H1, then paragraph, H2, paragraph, H3, paragraph, and a second H2/H3 set so we can see whether the problem repeats consistently or only hits the first instance.

When you paste, build it with real Divi heading modules (or set the Text module's H1/H2/H3 properly), not by making big bold text. We need the actual heading tags for this to tell us anything.

H1 HEADLINE The Standard Test Post for Layout Checking

This is an ordinary opening paragraph. It exists to establish what normal body text looks like on the page. Notice the spacing above it and below it. We want to see how much room sits between this paragraph and the heading that follows, because that gap is the thing we are chasing. Read it as plain filler and nothing more.

H2 How the First Section Behaves

Here is the first paragraph under an H2 heading. The distance between the heading directly above and this line is the exact measurement we care about. If there is a large, awkward gap here, we have reproduced the problem on fresh content, which tells us it lives in a global setting or a script and not in your old posts.

H3 A Smaller Subsection Under the First

This paragraph sits below an H3 heading. Compare the gap here to the gap under the H2 above it. If both are too large, the spacing rule is hitting every heading level. If only one is off, the problem is specific to a single heading level, which narrows things down considerably.

H2 How the Second Section Behaves

This is a second paragraph under a second H2. We include a repeat so we can confirm the behavior is consistent. If the first H2 looked wrong and this one looks fine, that points at a per-module override on the first. If both look identically wrong, it is global.

H3 Another Subsection for Good Measure

And this is a final paragraph under a second H3, closing out the test. By now you should be able to eyeball whether the heading-to-paragraph spacing is uniform across the whole post or scattered. That single observation tells us most of what we need to know.