diff --git a/sources/keybinds.js b/sources/keybinds.js
index 3a9d54b..171048c 100644
--- a/sources/keybinds.js
+++ b/sources/keybinds.js
@@ -143,11 +143,12 @@ var KeyboardManager = GObject.registerClass(
 					const handle = this._state.monitors[mon].focused;
 					const window = this._state.windows.find((x) => x.handle === handle);
 					if (!window) return;
-					this._focusNext();
+					log("Sending", handle.get_title(), "to tagNbr", tagNbr);
+					this._focusNext(true);
 					window.tags = tag;
 					window.handle.change_workspace_by_index(tagNbr, false);
 					this._renderer.renderAll();
-					this._indicator.update(mon);
+					this._indicator.update();
 				});
 				this._addBinding(`addto-tag-${tagNbr + 1}`, () => {
 					const mon = global.display.get_current_monitor();
@@ -157,7 +158,7 @@ var KeyboardManager = GObject.registerClass(
 					if (window.tags & tag) window.tags &= ~tag;
 					else window.tags |= tag;
 					this._renderer.renderAll();
-					this._indicator.update(mon);
+					this._indicator.update();
 				});
 			}
 			this._addBinding("set-tag-all", () => {
@@ -216,7 +217,7 @@ var KeyboardManager = GObject.registerClass(
 			this._indicator.update(mon);
 		}
 
-		_focusNext() {
+		_focusNext(skipRender) {
 			const mon = global.display.get_current_monitor();
 			const state = this._state.monitors[mon];
 			const idx = this._state.workIndexByHandle(state.focused);
@@ -226,7 +227,8 @@ var KeyboardManager = GObject.registerClass(
 			} else {
 				state.focused = null;
 			}
-			this._renderer.render(mon);
+			if (!skipRender)
+				this._renderer.render(mon);
 		}
 	}
 );
diff --git a/sources/renderer.js b/sources/renderer.js
index 023a36d..9df0001 100644
--- a/sources/renderer.js
+++ b/sources/renderer.js
@@ -156,7 +156,9 @@ var Renderer = GObject.registerClass(
 				),
 				global.display.connect("window-entered-monitor", (_display, _monitor, handle) => {
 					const [oldW, newW] = this._state.updateByHandle(handle);
-					log("Monitor changed for window", oldW.handle.get_title(), oldW.monitor, "to", newW.monitor);
+					// Update by handle return null if the window is not tracked yet (new window).
+					if (!oldW) return;
+					log("Monitor changed for window", newW.handle.get_title(), oldW.monitor, "to", newW.monitor);
 					if (oldW) this.render(oldW.monitor);
 					if (newW) this.render(newW.monitor);
 					this._indicator.update();
@@ -259,7 +261,8 @@ var Renderer = GObject.registerClass(
 					}
 					if (!this._isValidWindow(handle)) return;
 					const [oldW, newW] = this._state.updateByHandle(handle);
-					log("Workspace changed for window", oldW.handle.get_title(), oldW.tags, "to", newW.tags);
+					if (!oldW) return;
+					log("Workspace changed for window", newW.handle.get_title(), oldW.tags, "to", newW.tags);
 					if (oldW) this.render(oldW.monitor);
 					if (newW) this.render(newW.monitor);
 					this._indicator.update();
@@ -331,10 +334,10 @@ var Renderer = GObject.registerClass(
 
 			if (this._state.singleTagset) {
 				for (let i = 0; i < global.display.get_n_monitors(); i++) {
-					if (this._state.monitors[i] & tags && mon !== i) {
+					if (this._state.monitors[i].tags & tags && mon !== i) {
 						// Remove the selected tag from other monitors.
 						// If the other monitor had only this tag, swap monitor's tags instead.
-						this._state.monitors[i] = this._state.monitors[i] & ~tags || currTags;
+						this._state.monitors[i].tags = this._state.monitors[i].tags & ~tags || currTags;
 						this._setGWorkspaceIfNeeded(i);
 						this.render(i);
 					}
diff --git a/sources/state.js b/sources/state.js
index 7d3289e..df0e14c 100644
--- a/sources/state.js
+++ b/sources/state.js
@@ -36,27 +36,15 @@ var StateManager = GObject.registerClass(
 			this.windows = [];
 		}
 
-		/**
-		 * @param {Meta.Window} handle
-		 * @returns {FairyWindow}
-		 */
-		_windowFromHandle(handle) {
-			const mon = handle.get_monitor();
-			const tags = this.monitors[mon].tags;
-			return {
-				handle,
-				monitor: mon,
-				tags,
-				// Needed for the popByActor that might get called when the actor is already deleted
-				actor: handle.get_compositor_private(),
-			};
-		}
-
 		/**
 		 * @param {Meta.Window} handle
 		 */
 		newWindow(handle) {
-			const window = this._windowFromHandle(handle);
+			const window = {
+				handle,
+				monitor: handle.get_monitor(),
+				tags: this.monitors[handle.get_monitor()].tags,
+			};
 			this.monitors[window.monitor].beforeZoom = null;
 			log("New window", window.handle.get_title(), "on tag", window.tags, "monitor", window.monitor);
 			this.windows.unshift(window);
@@ -64,12 +52,17 @@ var StateManager = GObject.registerClass(
 
 		/**
 		 * @param {Meta.Window} handle
-		 * @returns {[FairyWindow, FairyWindow]} [old, new]
+		 * @returns {[FairyWindow, FairyWindow] | [null, null]} [old, new]
 		 */
 		updateByHandle(handle) {
 			const i = this.windows.findIndex((x) => x.handle === handle);
+			if (i === -1) return [null, null];
 			const old = { ...this.windows[i] };
-			this.windows[i] = this._windowFromHandle(handle);
+			this.windows[i] = {
+				handle,
+				monitor: handle.get_monitor(),
+				tags: 0b1 << handle.get_workspace().index(),
+			};
 			return [old, this.windows[i]];
 		}