Version

3.2.31

Reproduction link

sfc.vuejs.org/

Steps to reproduce

1.Enter any value in the C input box 2.The number after 'enter to monitor formdata -- > {a, B}' on the page indicates the number of monitoring triggers

What is expected?

Monitoring should not be triggered

What is actually happening?

Listening triggered

It's expected. You are rerendering the HelloWorld component when you change c and it creates a new object for the formData prop every time.