If your girlfriend starts testing you, you can try to communicate with her first to understand why she is doing this. If she tries to understand your behavior just because she is insecure, you can help her build more trust through patience and understanding. At the same time, you can also express your love and concern to her through your own actions and words, so that she can feel your true love.
However, if the probing behavior involves unhealthy behavior, such as checking the other person's mobile phone or social media account, then you need to seriously consider the impact of this behavior on your relationship. You can choose to have a frank talk with your girlfriend, tell her your feelings and worries, and discuss how to solve this problem together. If this behavior continues, it may lead to the damage of trust and relationship between two people, and eventually lead to breaking up.
In a word, it is normal to like to test a boyfriend's behavior in some cases, but if it is too frequent or involves unhealthy behavior, it may damage the trust and relationship between two people. When dealing with this kind of problem, the most important thing is to be frank, understanding and patient, and discuss with your girlfriend how to solve the problem and establish a healthier and more stable relationship.