diff --git a/apps/server/src/orchestration-v2/MilestoneDecider.test.ts b/apps/server/src/orchestration-v2/MilestoneDecider.test.ts
index ba196c561be2d..5d255eea41a72 100644
--- a/apps/server/src/orchestration-v2/MilestoneDecider.test.ts
+++ b/apps/server/src/orchestration-v2/MilestoneDecider.test.ts
@@ -34,6 +34,7 @@ function record(
       rejections.push(decision.message);
       continue;
     }
+    if (decision._tag !== "accepted") continue;
     log.push(
       milestoneTurnItem({
         base: {
@@ -102,6 +103,54 @@ describe("decideMilestoneAction", () => {
     expect(statuses(state)).toEqual(["m1:s1:active"]);
   });
 
+  it("keeps the active milestone when started again by its own title", () => {
+    const { state, items, rejections } = record([
+      [RUN_1, { action: "plan", titles: ["Preparar", "Verificar"] }],
+      [RUN_1, { action: "start", title: "Preparar" }],
+    ]);
+    expect(rejections).toEqual([]);
+    expect(items).toHaveLength(1);
+    expect(statuses(state)).toEqual(["m1:s1:active", "m2:s1:planned"]);
+    expect(decideMilestoneAction(state, { action: "start", title: "  preparar " })).toMatchObject({
+      _tag: "unchanged",
+    });
+  });
+
+  it.each([
+    ["the same title", "Verificar"],
+    ["a title differing in case and whitespace", "  vERIFICAR  "],
+  ])("starts the planned milestone with %s", (_name, title) => {
+    const { state, items } = record([
+      [RUN_1, { action: "plan", titles: ["Preparar", "Verificar", "Verificar"] }],
+      [RUN_1, { action: "start", title }],
+    ]);
+    expect(items.at(-1)).toMatchObject({
+      event: "started",
+      milestoneId: "m2",
+      setId: "s1",
+      title: "Verificar",
+      closedMilestoneId: "m1",
+    });
+    expect(statuses(state)).toEqual(["m1:s1:done", "m2:s1:active", "m3:s1:planned"]);
+  });
+
+  it("starts a new milestone when the title matches only a closed one", () => {
+    const { state } = record([
+      [RUN_1, { action: "plan", titles: ["Preparar", "Verificar"] }],
+      [RUN_1, { action: "start" }],
+      [RUN_1, { action: "drop", id: "m2", reason: "skipped" }],
+      [RUN_1, { action: "start", title: "Preparar" }],
+      [RUN_1, { action: "start", title: "verificar" }],
+    ]);
+    expect(statuses(state)).toEqual(["m1:s1:done", "m2:s1:dropped", "m3:s1:done", "m4:s1:active"]);
+    expect(state.milestones.map(({ title }) => title)).toEqual([
+      "Preparar",
+      "Verificar",
+      "Preparar",
+      "verificar",
+    ]);
+  });
+
   it.each<[string, ReadonlyArray<OrchestrationV2MilestoneAction>, string]>([
     ["start with nothing planned", [{ action: "start" }], "Nothing planned"],
     [
diff --git a/apps/server/src/orchestration-v2/MilestoneDecider.ts b/apps/server/src/orchestration-v2/MilestoneDecider.ts
index 22d65b447f309..a47ed4c7befe1 100644
--- a/apps/server/src/orchestration-v2/MilestoneDecider.ts
+++ b/apps/server/src/orchestration-v2/MilestoneDecider.ts
@@ -212,7 +212,8 @@ function currentMilestoneSetId(
 
 export type MilestoneDecision =
   | { readonly _tag: "accepted"; readonly detail: MilestoneItemDetail }
-  | { readonly _tag: "rejected"; readonly message: string };
+  | { readonly _tag: "rejected"; readonly message: string }
+  | { readonly _tag: "unchanged" };
 
 const rejected = (message: string): MilestoneDecision => ({ _tag: "rejected", message });
 const accepted = (detail: Omit<MilestoneItemDetail, "type">): MilestoneDecision => ({
@@ -220,6 +221,8 @@ const accepted = (detail: Omit<MilestoneItemDetail, "type">): MilestoneDecision
   detail: { type: "milestone", ...detail },
 });
 
+const titleKey = (title: string) => title.trim().toLowerCase();
+
 /** Validates one action against the current state. Pure: the caller builds and applies the item. */
 export function decideMilestoneAction(
   state: MilestoneState,
@@ -251,6 +254,22 @@ export function decideMilestoneAction(
         ...(action.note === undefined ? {} : { note: action.note }),
       };
       if (action.title !== undefined) {
+        const key = titleKey(action.title);
+        const current = milestones.filter(
+          (milestone) =>
+            milestone.setId === setId && isOpen(milestone) && titleKey(milestone.title) === key,
+        );
+        const planned = current.find((milestone) => milestone.status === "planned");
+        if (planned !== undefined) {
+          return accepted({
+            event: "started",
+            milestoneId: planned.id,
+            setId: planned.setId,
+            title: planned.title,
+            ...closing,
+          });
+        }
+        if (current.length > 0) return { _tag: "unchanged" };
         return accepted({
           event: "started",
           milestoneId: nextId(),
diff --git a/apps/server/src/orchestration-v2/Orchestrator.ts b/apps/server/src/orchestration-v2/Orchestrator.ts
index 04ac348792693..ba5c8c66615fb 100644
--- a/apps/server/src/orchestration-v2/Orchestrator.ts
+++ b/apps/server/src/orchestration-v2/Orchestrator.ts
@@ -9615,6 +9615,7 @@ const makeOrchestrator = Effect.fn("orchestrationV2.Orchestrator.layer")(functio
         detail: decision.message,
       });
     }
+    if (decision._tag === "unchanged") return;
     const now = yield* DateTime.now;
     const turnItem = milestoneTurnItem({
       base: {
diff --git a/docs/orchestration-v2/orchestrator-mcp-server.md b/docs/orchestration-v2/orchestrator-mcp-server.md
index 88dcf356598d9..199bee5927480 100644
--- a/docs/orchestration-v2/orchestrator-mcp-server.md
+++ b/docs/orchestration-v2/orchestrator-mcp-server.md
@@ -480,7 +480,9 @@ running turn (`parent_not_active` otherwise) and is hidden from delegated
 children. Actions:
 
 - `plan` opens a new set and starts its first milestone;
-- `start` begins the next planned milestone, one by `id`, or a new one by `title`;
+- `start` begins the next planned milestone, one by `id`, or one by `title`: a
+  planned one of that title in the current set, nothing if it is the active one,
+  otherwise a new one;
 - `done`, `change`, and `drop` act on one milestone; and
 - `post` attaches a note and images (absolute paths on the server) to the
   active one.