Test Wi-Fi on the actual viewing device and location. Signal strength, obstacles, neighbouring networks and household load can change playback even when a speed test briefly reports a high rate.
Choose a band by measured results
Compare the bands supported by both router and device. A stronger connection is more useful than choosing a band by its label. Do not assume 5 GHz or 6 GHz is available on every device or that it will be strongest in every room.
Reduce avoidable interference
- Compare playback nearer the router without changing the account.
- Check whether obstacles or the TV enclosure affect reception.
- Pause large household transfers for a short controlled test.
- Compare Ethernet if the device supports it.
If the result varies by time
Repeat at the normal viewing time and note other household usage. Compare several sources. A busy network and an unavailable individual source can create similar symptoms but require different fixes.