Adding/removing a paragraph instance affects fields in the other instances

I've encountered an unexpected behaviour of paragraphs.

Steps to reproduce:

In an existing node type:

1. Create a controlling field A (e.g., an option list for car makes: Fiat, Audi, and Honda)

2. Create paragraph field P with unlimited values (i.e. instances)

3. Create a dependent field B: an option list (e.g. car make models) with some default values

4. Add AJAX so that changes in A result in changes in B

Testing:

5. Choose Honda from A. B should now show only Honda models (e.g., Civic and Accord).

6. Add another instance of P. The options in field B are reset to the default values.

It seems that the existing instance of the paragraph (and/or its contents) is reloaded when another one is created (or removed).

Is this behaviour expected?