Weird stutter in ECS when rotating cube

Hi, I've been trying to program in ECS lately as it is still new to me, and I encountered an issue when attempting to create a spinning cube.

this is my current code

 using Unity.Entities;
 using Unity.Jobs;
 using Unity.Transforms;
 using UnityEngine;
 
 [AlwaysSynchronizeSystem]
 public class CubeRotationSystem : JobComponentSystem
 {
     protected override JobHandle OnUpdate(JobHandle inputDeps)
     {
         float deltaTime = World.Time.DeltaTime;
         Entities.ForEach((ref Rotation rot, in CubeRotationData data) =>
         {
             Quaternion rotation = Quaternion.Euler(data.direction * data.speed * deltaTime);
             rot.Value = rot.Value * rotation;
         }).Run();
         return default;
     }
 }

data.directly contains a float3 of the direction and data.speed a float of... well the speed, the data never changes on this level.

the cube correctly spins but like every 5 seconds or so I can see that the cube kind of stutters before restarting to turn properly

where do you think the problem could come from ?