Merge branch 'feature/JAL-2587' into documentation/JAL-2675_release2102b1

diff --cc src/jalview/renderer/OverviewRenderer.java
index 73f66f0,1f3f663..1c50aab
--- 1/src/jalview/renderer/OverviewRenderer.java
--- 2/src/jalview/renderer/OverviewRenderer.java
+++ b/src/jalview/renderer/OverviewRenderer.java
@@@ -162,9 -146,10 +163,11 @@@ public class OverviewRendere
              }
            }
  
-           sendProgressUpdate((pixelCol + 1) * (endRow - pixelRow),
-                   totalPixels, lastRowUpdate);
+           // store last update value
+           lastUpdate = sendProgressUpdate(
+                   (pixelCol + 1) * (endRow - pixelRow), totalPixels,
+                   lastRowUpdate, lastUpdate);
 +
            pixelCol = endCol + 1;
          }
          colIndex++;