TicketSignup gives your event the option to enable a clear button on the ticket confirmation page, which allows ticket purchasers to clear their purchase within a 15 minute window when they remain on the confirmation page.
If you created your ticket event BEFORE November 2nd, the clear option is ON by default for all ticket purchasers. If your ticket event was created AFTER November 2nd, the clear option is OFF by default for all ticket purchasers. You can enable or disable the option to allow the clear option by navigating to Events >> Purchase Settings >> Sales Closed Settings. Check or uncheck the setting to allow cleared purchases and click Save.