Separate delivery from retention
One question is whether water reaches the washer through the required supplies and unrestricted hoses. Another is whether the installation allows water to leave while the machine is trying to fill. Those branches need different inspection, even though both may look like slow filling. Record whether the message appears on every temperature selection, whether plumbing work preceded it, and whether the washer was moved. Do not use those observations as permission to dismantle an inlet assembly.