@Override
		public void buttonPressed(FieldLocation location, Field field, MouseEvent ev) {
			// FieldPanel won't notify this listener for drag or button3 events.
			// This only wants to deal with left click to set highlight block to selected.
			if (ev.getButton() != MouseEvent.BUTTON1) {
				return;
			}

			// Listing Panel creates the selection when doing click or drag with Ctrl or Shift.
			if (DockingUtils.isControlModifier(ev) || ev.isShiftDown()) {
				return;
			}

			ProgramLocation pLoc = null;
			if (field instanceof ListingField lf) {
				FieldFactory factory = lf.getFieldFactory();
				pLoc = factory.getProgramLocation(location.getRow(), location.getCol(), lf);
			}

			// if clicked in dummy field, try and find the address for the white space.
			if (pLoc == null) {
				AddressIndexMap indexMap = diffListingPanel.getAddressIndexMap();

				Address addr = indexMap.getAddress(location.getIndex());

				if (addr != null && secondaryDiffProgram != null) {
					pLoc = new ProgramLocation(secondaryDiffProgram, addr);
				}
				else {
					return; // pLoc is null
				}
			}

			Address addr = pLoc.getAddress();
			if (!p2Selection.contains(addr)) {
				// Left click in a Diff highlight selects it and only it.
				// Left click outside all highlight blocks clears the selection.
				AddressSet set = new AddressSet(); // Start with no selection.
				if (p2DiffHighlight.contains(addr)) {
					// If clicked in a Diff Highlight then make that the selection.
					AddressRange range = p2DiffHighlight.getRangeContaining(addr);
					if (range != null) {
						set = new AddressSet(range);
					}
				}

				if (set.equals(p2Selection)) {
					return; // Selection is unchanged so do nothing.
				}
				MarkerSet selectionMarkers = getSelectionMarkers();
				selectionMarkers.clearAll();

				programSelectionChanged(new ProgramSelection(p2AddressFactory, set),
					EventTrigger.GUI_ACTION);
				updatePgm2Enablement();
			}
		}
Reload the marked differences in the diff panel.
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/ProgramDiffPlugin.java