An Ethernet link can fail intermittently because of a loose connector, damaged cable or stressed socket. A visible network icon does not prove every moment of the connection is healthy. Try a known working cable before changing account details.
Inspect without dismantling
Look for crushed sections, sharp bends and connectors that do not latch securely. Keep cables away from door pressure and trip hazards. Do not open electrical equipment or attempt unsafe repairs to investigate an ordinary network fault.
Change one component
Use another suitable cable and, if available, another known working router port. Keep the player and source unchanged. If both are changed together, you will know the path improved but not which component caused the difference.
Watch link behaviour
Some devices or routers show link status and errors. Compare those observations with the interruption time. A port that repeatedly disconnects deserves hardware investigation; a source-specific failure with a stable link points elsewhere.
