Jittery Issue with Vuforia 7 in Unity (Android & iOS)

Hello, I am very friendly with using Vuforia plugin in Unity for AR development. Currently i am working on a big project where i am using Vuforia for multiple trackers. But the thing is that the printed tracker images are mounted on beacon and this beacons are placed into the open area and because of open area(day light) my AR experience start shaking continuously(constant jitters). But if i play the same experience inside a room(indoor light/office cabins) it plays well without any jitters.

    It is my question to you - What are the limitations for trackers and Vuforia plugin? Because i am planning to purchase legal license for my current project but after such experience with Vuforia we hold this process.

    If anybody has faced this jittery issue before,i would really like to hear about how they overcame this.

    It is request to you please suggest me that what things should i need to avoid or need to be taken care.

    Please.