Index: /trunk/src/org/openstreetmap/josm/gui/io/BasicUploadSettingsPanel.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/io/BasicUploadSettingsPanel.java	(revision 15801)
+++ /trunk/src/org/openstreetmap/josm/gui/io/BasicUploadSettingsPanel.java	(revision 15802)
@@ -4,4 +4,5 @@
 import static org.openstreetmap.josm.tools.I18n.tr;
 
+import java.awt.BorderLayout;
 import java.awt.GridBagLayout;
 import java.awt.event.ActionEvent;
@@ -177,9 +178,9 @@
 
     protected void build() {
-        setLayout(new GridBagLayout());
+        setLayout(new BorderLayout());
         setBorder(BorderFactory.createEmptyBorder(3, 3, 3, 3));
-        add(buildUploadCommentPanel(), GBC.eol().fill(GBC.BOTH));
-        add(pnlUploadParameterSummary, GBC.eol().fill(GBC.BOTH));
-        add(cbRequestReview, GBC.eol().fill(GBC.BOTH));
+        add(buildUploadCommentPanel(), BorderLayout.NORTH);
+        add(pnlUploadParameterSummary, BorderLayout.CENTER);
+        add(cbRequestReview, BorderLayout.SOUTH);
         cbRequestReview.addItemListener(e -> changesetReviewModel.setReviewRequested(e.getStateChange() == ItemEvent.SELECTED));
     }
Index: /trunk/src/org/openstreetmap/josm/gui/io/UploadDialog.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/io/UploadDialog.java	(revision 15801)
+++ /trunk/src/org/openstreetmap/josm/gui/io/UploadDialog.java	(revision 15802)
@@ -433,4 +433,6 @@
         @Override
         public Dimension getPreferredSize() {
+            // This probably fixes #18523. Don't know why. Don't know how. It just does.
+            super.getPreferredSize();
             // make sure the tabbed pane never grabs more space than necessary
             return super.getMinimumSize();