Stripe and tryout membership


I’m using this form tag, to generate a form Stripe, where a user pay 1 dollar to get a “Daily Membership” and the day after, he still pay 1 dollar.
But if He doesn’t pay the second time, (theorically) he should became a Free member.

[s2Member-Pro-Stripe-Form level="10" ccaps="tryout" desc="1 Day @ $1 / then $1 USD / Daily (recurring charge, for ongoing access)" cc="USD" custom="(website url)" ta="1" tp="1" tt="D" ra="1" rp="1" rt="D" rr="1" coupon="" accept_coupons="0" default_country_code="US" captcha="0" template="stripe_form_trial.php" success="(website url)"/]

But, currently s2member doesn’t downgrade my users.
Now: in s2member logs, I see this error:
> [s2member_log] => Array

                [0] => Stripe Webhook/IPN event type identified as: `invoice.payment_failed` on: Thu Jun 17, 2021 1:15:40 pm UTC
                [1] => Ignoring `invoice.payment_failed`. s2Member does NOT respond to individual payment failures; only to subscription cancellations.
                [2] => You may control the behavior(s) associated w/ subscription payment failures from your Stripe Dashboard please.

I’ve wrote to Stripe, and they wrote this:

As I see, you would like to know why the subscription of your customer

***** is still active, since he’s not paying.
Regarding this request, I took the time to carefully review your account
and as I see, the subscription status is not canceled but in “past due”: I fully understand that this topic can be a bit confusing and for this
reason, I would like to shed some light on this matter: Usually, when a
subscription is not paid, the subscription will automatically go “past
due” instead of being canceled and therefore the subscription of your
client is still active. In this case, what I can kindly recommend you in
order to prevent this from happening again, is to use the “payment
behavior” parameter and set it to default_incomplete [1]. Then you can
choose the option error_if_incomplete​so that when payment fails, then
subscription expires after 23 hours

What I’m wrong? Thanks!