You’ve reached the limit for development store orders with this payment processor. To place another order, you’ll need to use a test payment gateway. Learn more about testing orders in development stores.
Is it possible to get this changed - or is it time related?
Many thanks
This would be expected behaviour if you are trying to create orders with a payment provider not in test mode. To test orders on a Development Store you do need to ensure that the payment gateway is set to test mode, or processing the transactions as a test transaction.
Here’s some documentation with more specific information, including instructions on processing test transactions for Shopify Payments, the Bogus Test Gateway, and other 3rd party payment gateways.