When I create a new invoice, it instantly marks as paid and will not let me submit to client. Why does this keep happening?

Hi harri-cosby-gmai, please check your automation settings by navigating to the Cog > Account & settings > Advanced > Automation > Automatically apply credits. When enabled, this will automatically apply credits to the next invoice you create for the same customer. You can toggle the green slider to the left to turn this feature off. :)