Welcome to that precious feeling of control and social pressure. If you may think this may an incident and that specific JW is an exception, you'd be wrong.
JW will formally and informally check on you whatever you do, and pressure you do adhere to Watchtower rules, and be more and more and more involved in their cult religion. This will not stop after joining, it will only become worse.
I did everything right
If you mean you followed Watchtower rules then yes, you already submitted yourself to people as if you are under their authority and you're accountable to them.
Otherwise, getting involved with a high control group is 'doing everything right' if you value your free will, independence, agency and thinking for yourself.