Expired transactions

Hello. I'm stumbling upon an issue where transactions generated through the Xumm SDK are failing shortly if not immediately after being generated. The request itself is not failing as the QR code and websocket data are being generated properly, however, the socket sends an { expired: true } event shortly after the transaction is created. This is only happening in some transactions we generate and our team is wondering if this is a normal occurrence with the SDK and just something we should account for or if there is something not being submitted properly along the request