If you assign a manual membership to your clients, the next cycle the status will be marked as unpaid to make sure they don't have free access. You can change the status and grant them access again by following these steps:
Click on Sales then on Invoices. You can also find the invoices from a specific client by going to Clients and clicking on the client you want to see, there you have an Invoice tab.
2. Look for the invoice you want to edit and click on the number.
3. Click on the 3 dots next to the invoice number and then on Change invoice status.
4. Mark the invoice as Paid and choose the right payment method. You can also add a note if you want.
5. Click on Update status and now your client will have access again.