diff --git a/server/src/service/business/maintenanceWindowService.ts b/server/src/service/business/maintenanceWindowService.ts
index 541b028f5..5d7a05b7d 100644
--- a/server/src/service/business/maintenanceWindowService.ts
+++ b/server/src/service/business/maintenanceWindowService.ts
@@ -55,6 +55,24 @@ export class MaintenanceWindowService implements IMaintenanceWindowService {
 		return MaintenanceWindowService.SERVICE_NAME;
 	}
 
+	private flipMonitorsLeavingMaintenance = async (monitorIds: string[], teamId: string, excludeWindowId: string, now: Date): Promise<void> => {
+		if (monitorIds.length === 0) return;
+
+		const otherWindows = await this.maintenanceWindowsRepository.findByMonitorIds(monitorIds, teamId, excludeWindowId);
+		const stillCovered = new Set<string>();
+		for (const otherWindow of otherWindows) {
+			if (!isWindowActive(otherWindow, now)) continue;
+			for (const monitorId of otherWindow.monitorIds) {
+				if (monitorIds.includes(monitorId)) stillCovered.add(monitorId);
+			}
+		}
+
+		const toInitializing = monitorIds.filter((monitorId) => !stillCovered.has(monitorId));
+		if (toInitializing.length > 0) {
+			await this.monitorsRepository.updateByIds(toInitializing, teamId, { status: "initializing" });
+		}
+	};
+
 	createMaintenanceWindow = async ({
 		teamId,
 		monitorIDs,
@@ -134,7 +152,14 @@ export class MaintenanceWindowService implements IMaintenanceWindowService {
 	};
 
 	deleteMaintenanceWindow = async ({ id, teamId }: { id: string; teamId: string }) => {
-		return await this.maintenanceWindowsRepository.deleteById(id, teamId);
+		const deleted = await this.maintenanceWindowsRepository.deleteById(id, teamId);
+
+		const now = new Date();
+		if (isWindowActive(deleted, now)) {
+			await this.flipMonitorsLeavingMaintenance(deleted.monitorIds, teamId, deleted.id, now);
+		}
+
+		return deleted;
 	};
 
 	editMaintenanceWindow = async ({
@@ -180,18 +205,7 @@ export class MaintenanceWindowService implements IMaintenanceWindowService {
 		}
 
 		if (leavingCandidates.length > 0) {
-			const otherWindows = await this.maintenanceWindowsRepository.findByMonitorIds(leavingCandidates, teamId, existing.id);
-			const stillCovered = new Set<string>();
-			for (const otherWindow of otherWindows) {
-				if (!isWindowActive(otherWindow, now)) continue;
-				for (const monitorId of otherWindow.monitorIds) {
-					if (leavingCandidates.includes(monitorId)) stillCovered.add(monitorId);
-				}
-			}
-			const toInitializing = leavingCandidates.filter((monitorId) => !stillCovered.has(monitorId));
-			if (toInitializing.length > 0) {
-				await this.monitorsRepository.updateByIds(toInitializing, teamId, { status: "initializing" });
-			}
+			await this.flipMonitorsLeavingMaintenance(leavingCandidates, teamId, existing.id, now);
 		}
 
 		return updated;
diff --git a/server/test/unit/services/maintenanceWindowService.test.ts b/server/test/unit/services/maintenanceWindowService.test.ts
index ee3615d97..a51fd5703 100644
--- a/server/test/unit/services/maintenanceWindowService.test.ts
+++ b/server/test/unit/services/maintenanceWindowService.test.ts
@@ -233,6 +233,49 @@ describe("MaintenanceWindowService", () => {
 			expect(result).toBe(deleted);
 			expect(maintenanceWindowsRepository.deleteById).toHaveBeenCalledWith("mw-1", "team-1");
 		});
+
+		it("does not touch monitor status when deleting an inactive window", async () => {
+			// default fixture has past dates → inactive
+			const { service, monitorsRepository, maintenanceWindowsRepository } = createService();
+
+			await service.deleteMaintenanceWindow({ id: "mw-1", teamId: "team-1" });
+
+			expect(monitorsRepository.updateByIds).not.toHaveBeenCalled();
+			expect(maintenanceWindowsRepository.findByMonitorIds).not.toHaveBeenCalled();
+		});
+
+		it("flips covered monitors to initializing when deleting an active window", async () => {
+			const maintenanceWindowsRepository = createMaintenanceWindowsRepo();
+			(maintenanceWindowsRepository.deleteById as jest.Mock).mockResolvedValue(makeActiveWindow({ monitorIds: ["mon-1", "mon-2"] }));
+			const { service, monitorsRepository } = createService({ maintenanceWindowsRepository });
+
+			await service.deleteMaintenanceWindow({ id: "mw-1", teamId: "team-1" });
+
+			expect(monitorsRepository.updateByIds).toHaveBeenCalledTimes(1);
+			expect(monitorsRepository.updateByIds).toHaveBeenCalledWith(["mon-1", "mon-2"], "team-1", { status: "initializing" });
+		});
+
+		it("excludes the deleted window from the overlap check", async () => {
+			const maintenanceWindowsRepository = createMaintenanceWindowsRepo();
+			(maintenanceWindowsRepository.deleteById as jest.Mock).mockResolvedValue(makeActiveWindow({ monitorIds: ["mon-1"] }));
+			const { service } = createService({ maintenanceWindowsRepository });
+
+			await service.deleteMaintenanceWindow({ id: "mw-1", teamId: "team-1" });
+
+			expect(maintenanceWindowsRepository.findByMonitorIds).toHaveBeenCalledWith(["mon-1"], "team-1", "mw-1");
+		});
+
+		it("does not flip a monitor still covered by another active window", async () => {
+			const maintenanceWindowsRepository = createMaintenanceWindowsRepo();
+			(maintenanceWindowsRepository.deleteById as jest.Mock).mockResolvedValue(makeActiveWindow({ monitorIds: ["mon-1", "mon-2"] }));
+			(maintenanceWindowsRepository.findByMonitorIds as jest.Mock).mockResolvedValue([makeActiveWindow({ id: "mw-2", monitorIds: ["mon-2"] })]);
+			const { service, monitorsRepository } = createService({ maintenanceWindowsRepository });
+
+			await service.deleteMaintenanceWindow({ id: "mw-1", teamId: "team-1" });
+
+			expect(monitorsRepository.updateByIds).toHaveBeenCalledTimes(1);
+			expect(monitorsRepository.updateByIds).toHaveBeenCalledWith(["mon-1"], "team-1", { status: "initializing" });
+		});
 	});
 
 	// ── editMaintenanceWindow ────────────────────────────────────────────────