A software developer's months-long investigation into mysterious WiFi problems revealed an unexpected culprit in 2020 - a digital painting application was causing system-wide network disruptions due to a programming framework bug.
The issue manifested as severe latency spikes occurring every few seconds, making video calls drop and online games unplayable. What made the problem particularly puzzling was that it only affected desktop computers, while other devices worked normally in the same location.
Multiple attempts at resolving the issue - including purchasing new WiFi adapters, building an entirely new computer system, and adjusting network settings - proved futile. The breakthrough came when the user systematically tested different applications running on the system.
The source was eventually traced to MediBang Paint Pro, a digital art program. Further investigation revealed the root cause: the Qt5 programming framework used by the application was aggressively polling network interfaces every 10 seconds, leading to connection disruptions across the entire system.
This behavior stemmed from a documented bug in versions of Qt5 before 5.14, where its network management component would repeatedly check for WiFi interface changes, regardless of whether network functionality was actively needed.
The simple fix involved setting an environment variable to disable this polling behavior. However, the obscure nature of the bug led to months of troubleshooting, as few users would suspect their drawing software could cause WiFi problems.
This case highlights how modern software's complex dependencies can create unexpected system-wide issues, and demonstrates the challenge of diagnosing problems when the apparent cause seems unrelated to the symptoms.