When I do paid on one invoice then the following invoices will come up paid aswell and it shows when I send it to the client as paid when it's not

Hello Fraserbrookman-g, 

Welcome to the Community page, 

It is most like you have the setting turned on for applying bill payments automatically, if you follow these steps to turn it off it will then not happen any more for you. Main cog wheel> account and settings>advanced>Automation> toggle it off - (automatically apply bill payments)> save>Done