Invoices: Change expected behaviour for switches in numbering scheme

src/pretix/base/models/_transactions.py

@@ -36,7 +36,7 @@ from django.db import transaction
 dirty_transactions = threading.local()
 
 logger = logging.getLogger(__name__)
-fail_loudly = os.getenv('PRETIX_DIRTY_TRANSACTIONS_QUIET', 'false') not in ('true', 'True', 'on', '1')
+fail_loudly = os.getenv('PRETIX_DIRTY_TRANSACTIONS_QUIET', 'false' if settings.DEBUG else 'true') not in ('true', 'True', 'on', '1')
 
 
 class DirtyTransactionsForOrderException(Exception):

src/pretix/base/models/invoices.py

@@ -237,7 +237,7 @@ class Invoice(models.Model):
     def _get_invoice_number_from_order(self):
         return '{order}-{count}'.format(
             order=self.order.code,
-            count=Invoice.objects.filter(event=self.event, order=self.order).count() + 1,
+            count=Invoice.objects.filter(event=self.event, prefix=self.prefix, invoice_no__startswith=f"{self.order.code}-", order=self.order).count() + 1,
         )
 
     def save(self, *args, **kwargs):