diff --git a/mon/mon.js b/mon/mon.js
index 1338ee89..04738446 100644
--- a/mon/mon.js
+++ b/mon/mon.js
@@ -627,7 +627,7 @@ class Mon
                 if (this.state.pg.history[pool_id] &&
                     this.state.pg.history[pool_id][pg])
                 {
-                    pg_history[pg-1] = this.state.pg.history[pool_id][pg];
+                    pg_history[pg-1] = JSON.parse(JSON.stringify(this.state.pg.history[pool_id][pg]));
                 }
             }
             const real_prev_pgs = [];
diff --git a/mon/pg_utils.js b/mon/pg_utils.js
index 082d94f2..64e3370f 100644
--- a/mon/pg_utils.js
+++ b/mon/pg_utils.js
@@ -102,7 +102,7 @@ function scale_pg_count(prev_pgs, new_pg_count)
     {
         for (let i = prev_pgs.length; i < new_pg_count; i++)
         {
-            prev_pgs[i] = prev_pgs[i % prev_pgs.length];
+            prev_pgs[i] = [ ...prev_pgs[i % prev_pgs.length] ];
         }
     }
     else if (prev_pgs.length > new_pg_count)