diff --git a/InitUiElements.ts b/InitUiElements.ts
index dfd5b4439..e7113e2d6 100644
--- a/InitUiElements.ts
+++ b/InitUiElements.ts
@@ -454,7 +454,7 @@ export class InitUiElements {
                             return false;
                         }
 
-                        if (z >= clustering.maxZoom) {
+                        if (z > clustering.maxZoom) {
                             return true
                         }
 
diff --git a/Logic/SimpleMetaTagger.ts b/Logic/SimpleMetaTagger.ts
index 4cf5a8c47..b0e4d50bf 100644
--- a/Logic/SimpleMetaTagger.ts
+++ b/Logic/SimpleMetaTagger.ts
@@ -209,7 +209,7 @@ export default class SimpleMetaTagger {
                 configurable: true,
                 get: () => {
                     delete feature.properties._isOpen
-                    feature.properties._isOpen = ""
+                    feature.properties._isOpen = undefined
                     const tagsSource = State.state.allElements.getEventSourceById(feature.properties.id);
                     tagsSource.addCallbackAndRunD(tags => {
                         if (tags.opening_hours === undefined || tags._country === undefined) {
@@ -230,7 +230,8 @@ export default class SimpleMetaTagger {
                                 const oldNextChange = tags["_isOpen:nextTrigger"] ?? 0;
 
                                 if (oldNextChange > (new Date()).getTime() &&
-                                    tags["_isOpen:oldvalue"] === tags["opening_hours"]) {
+                                    tags["_isOpen:oldvalue"] === tags["opening_hours"]
+                                && tags["_isOpen"] !== undefined) {
                                     // Already calculated and should not yet be triggered
                                     return false;
                                 }
@@ -267,7 +268,7 @@ export default class SimpleMetaTagger {
                         }
 
                     })
-                    return feature.properties["_isOpen"]
+                    return undefined
                 }
             })
 
diff --git a/UI/SpecialVisualizations.ts b/UI/SpecialVisualizations.ts
index bc41f916c..9cdadec04 100644
--- a/UI/SpecialVisualizations.ts
+++ b/UI/SpecialVisualizations.ts
@@ -55,7 +55,11 @@ export default class SpecialVisualizations {
                             if (!tags.hasOwnProperty(key)) {
                                 continue
                             }
-                            parts.push([key, tags[key] ?? "<b>undefined</b>"]);
+                            let v = tags[key]
+                            if(v === ""){
+                                v = "<b>empty string</b>"
+                            }
+                            parts.push([key, v ?? "<b>undefined</b>"]);
                         }
                         
                         for(const key of calculatedTags){