A connection can behave differently when the household, local network or wider route is busy. Testing only in the morning may miss the problem. Compare several evenings using the same device, channel and connection before drawing a conclusion.
Separate recurring patterns
Note start time, duration and affected services. A single channel failing every evening may have a different cause from every device slowing down. Check whether game downloads or backups begin at the same time as the interruption.
Use a controlled comparison
Try a wired session at the usual problem time and compare another legitimate streaming source. These comparisons cannot identify every upstream issue, but they reveal whether wireless contention or a broader network slowdown is involved.
Report the evidence clearly
Give support the approximate time zone, programme, device and connection type, plus the result of the wired comparison. Avoid sending passwords or full playlist URLs. A concise recurring pattern is more useful than many unrelated speed-test screenshots.
