Fixed #9538

core/src/mindustry/ai/UnitGroup.java

@@ -19,8 +19,23 @@ public class UnitGroup{
     public int collisionLayer;
     public volatile float[] positions, originalPositions;
     public volatile boolean valid;
+    public long lastSpeedUpdate = -1;
     public float minSpeed = 999999f;
 
+    public void updateMinSpeed(){
+        if(lastSpeedUpdate == Vars.state.updateId) return;
+
+        lastSpeedUpdate = Vars.state.updateId;
+
+        for(Unit unit : units){
+            //don't factor in the floor speed multiplier
+            Floor on = unit.isFlying() ? Blocks.air.asFloor() : unit.floorOn();
+            minSpeed = Math.min(unit.speed() / on.speedMultiplier, minSpeed);
+        }
+
+        if(Float.isInfinite(minSpeed) || Float.isNaN(minSpeed)) minSpeed = 999999f;
+    }
+    
     public void calculateFormation(Vec2 dest, int collisionLayer){
         this.collisionLayer = collisionLayer;
 
@@ -33,19 +48,16 @@ public class UnitGroup{
         cy /= units.size;
         positions = new float[units.size * 2];
 
+
         //all positions are relative to the center
         for(int i = 0; i < units.size; i ++){
             Unit unit = units.get(i);
             positions[i * 2] = unit.x - cx;
             positions[i * 2 + 1] = unit.y - cy;
             unit.command().groupIndex = i;
-
-            //don't factor in the floor speed multiplier
-            Floor on = unit.isFlying() ? Blocks.air.asFloor() : unit.floorOn();
-            minSpeed = Math.min(unit.speed() / on.speedMultiplier, minSpeed);
         }
 
-        if(Float.isInfinite(minSpeed) || Float.isNaN(minSpeed)) minSpeed = 999999f;
+        updateMinSpeed();
 
         //run on new thread to prevent stutter
         Vars.mainExecutor.submit(() -> {

core/src/mindustry/ai/types/CommandAI.java

@@ -148,6 +148,10 @@ public class CommandAI extends AIController{
             }
         }
 
+        if(group != null){
+            group.updateMinSpeed();
+        }
+
         if(!net.client() && command == UnitCommand.enterPayloadCommand && unit.buildOn() != null && (targetPos == null || (world.buildWorld(targetPos.x, targetPos.y) != null && world.buildWorld(targetPos.x, targetPos.y) == unit.buildOn()))){
             var build = unit.buildOn();
             tmpPayload.unit = unit;