Automatic recurring plans with off-line payment

I have some members paid their membership off-line with bank transfer. If I set the bill as paid, I think there have to start a new period and a new bill. But it doesn't happen. What I'm doing wrong?

You can't do auto recurring payments with offline payments. They'll have to renew manually generating a new basket that can be paid from CBSubs > Baskets.

OK, thank you for your answer.
I have a recurring plan (monthly) with an offline payment. I renew it manually. But how I get a new invoice for the next period?

Renewing should generate a new basket, as long as you're doing so from frontend, for you to pay from within CBSubs > Baskets. Ensure you've clicked the confirmation link when using the offline payment method so the basket is put in a pending state to be paid.

I've to renew the subscription at the backend. Reason: my customer has an standing order every month. If I see the payment at my bank I renew the membership. But for my account staff I need an invoice.

Renewing from backend does not generate a basket. If you need a basket then you need to go through the frontend process of generating one then paying it within CBSubs > Baskets. There is no backend process for generating a basket. If they're doing direct payments to your bank consider using Stripe and its ACH Debit payment option and then you will no longer need to manage offline payments.