This is not an issue and it is by design. When you add the follow-up T4, it has a precondition indicating whether it should be activated based on the parent topic. It does not mean it will be activated immediately.
Consider the chat flow below. You want T2 to be activated before branching out.
Chatbot: What subject do you teach (T1)
choice: a) Math (b) English © Social Studies
Chatbot: How long have you been teaching the subject? (T2)
If T1 (a)
Chatbot: What’s the most difficult thing your students found in math?
Chatbot: What’s your favorite subject to teach in English?
You can always modify the flow. If you don’t wish T2 to be activated before each branch, you can always drag it AFTER the branched topics.