Heatmap changing in layout export

[Lazdona]

Using ArcGIS Pro, I am trying to export a heatmap (see first image). However, when I go to layout export, the heatmap changes (see second image). Indeed, the layout heatmap seems very bugged, and I cannot seem to change it to match what I am seeing in the map view at all no matter how much tweaking with the settings I do.

Note that "method" is set to "constant". Regenerating density makes minimal difference.

How can I fix this?

[MErikReedAugusta]

That actually looks like a scale/zoom issue.

From your first image, I see your Map View is at 1:5,697,933.  What's the scale for the Layout View?  And what zoom level are you at?

I often find myself working with larger print files, like ARCH-E (36x48 inches), and will get caught where I'm viewing things at 50% zoom so the page fits on my screen, but that's throwing off my assessment of whether or not my symbology is scaled properly for the way people will be interacting with the printed file.

I also run into scaling headaches like this, where the zoom levels look identical on screen, but the symbology scales don't.  Again, that's because I'm at 50% zoom, instead of comparing at 100% zoom.

Quick test/fix: Open the properties for your Map, and set a "Reference Scale" equal to 1:5,697,933.  See if that fixes your Layout issue.