diff --git a/app/src/main/java/it/reyboz/bustorino/backend/mato/MQTTMatoClient.kt b/app/src/main/java/it/reyboz/bustorino/backend/mato/MQTTMatoClient.kt
--- a/app/src/main/java/it/reyboz/bustorino/backend/mato/MQTTMatoClient.kt
+++ b/app/src/main/java/it/reyboz/bustorino/backend/mato/MQTTMatoClient.kt
@@ -139,19 +139,17 @@
 
     fun stopMatoRequests(responder: MQTTMatoListener){
         var removed = false
+
+
         for ((lineTopic,responderList)in respondersMap.entries){
-            var done = false
-            for (el in responderList){
-                if (el.get()==null){
-                    responderList.remove(el)
-                } else if(el.get() == responder){
-                    responderList.remove(el)
-                    done = true
-                }
-                if (done)
-                    break
+            val oldSize = responderList.size
+
+            responderList.removeIf {
+                (it.get()==null) || (it.get()==responder)
             }
-            if(done) Log.d(DEBUG_TAG, "Removed one listener for topic $lineTopic, listeners: $responderList")
+            val diffLength = responderList.size - oldSize
+            if(diffLength > 0)
+                Log.d(DEBUG_TAG, "Removed $diffLength listeners for topic $lineTopic, listeners: $responderList")
             //if (done) break
             if (responderList.isEmpty()){
                 //actually unsubscribe
@@ -169,14 +167,11 @@
                     Log.e(DEBUG_TAG, "Tried unsubscribing but there was an error in the client library:\n$e")
                 }
             }
-            removed = done || removed
+            removed = (diffLength>0) || removed
         }
         // check responders map, remove lines that have no responders
-
-        for(line in respondersMap.keys){
-            if(respondersMap[line]?.isEmpty() == true){
-                respondersMap.remove(line)
-            }
+        respondersMap.entries.removeIf {
+            it.value.isEmpty()
         }
         Log.d(DEBUG_TAG, "Removed: $removed, respondersMap: $respondersMap")
     }
diff --git a/app/src/main/java/it/reyboz/bustorino/map/MapLibreUtils.kt b/app/src/main/java/it/reyboz/bustorino/map/MapLibreUtils.kt
--- a/app/src/main/java/it/reyboz/bustorino/map/MapLibreUtils.kt
+++ b/app/src/main/java/it/reyboz/bustorino/map/MapLibreUtils.kt
@@ -78,15 +78,18 @@
 
         @JvmStatic
         fun findPointsToPutDirectionMarkers(polyPoints: List<LatLng>, stops: List<Stop>, distanceIcon: Double): List<Int>{
+            //output value
+            val pointsOutput = mutableListOf<Int>()
             val closestIndices = findIndicesClosestPointsForStops(polyPoints, stops)
             Log.d(DEBUG_TAG, "idcs: $closestIndices")
+            if(closestIndices.size==0)
+                return pointsOutput
 
             val distancesSec = mutableListOf<Double>()
             var pi = closestIndices[0]
             val cumulativeDist = mutableListOf<Double>()
             var sum = 0.0
 
-            val pointsOutput = mutableListOf<Int>()
             var nPoints = 0
             var distFromLastPoint = 0.0
             for(i in 1..<stops.size){