Culture Shock
Each Agile team creates its own culture. Moving between teams, and specifically Agile teams, is not only about different work or different team members to work with; it's mainly about adapting to different team cultures.
Team culture takes time to evolve and — like any other type of culture — it will resist a change, no matter how small it is. That change can be in the form of new person (like you), or it can be in the form of new idea that you want to implement.