Should I re-create my campaign after updating the payment settings?

If you update the Stripe keys on your platform, this could potentially affect the current campaigns that you have created before the update. There is a popup that explains this when you click on the save button in the payment settings page:

This will only apply to particular scenarios. You will not have to create a new campaign if you are using Direct Transactions ON, and switch to Direct Transactions OFF. This will not matter if you are in Live or Test mode or switch from Live to Test mode. Any other instance, it is recommended that you re-create the campaign if you want it to be running correctly after updating the Stripe keys.