@BlynkAndroidDev This has brought up memories of similar experiences, as in seemingly one-way connection for a short while, (but not while switching networks, as everything was running on an otherwise stable USB-link and wired local network & server connection at the time).
[Solved] Local Server connection and communication issues & Script keeps halting (on MEGA via USB link)
At the time I assumed it was the USB link… however as time goes on and I switched to ESP WiFi… one remaining constant is my older version Android devices and my primarily used Android emulator (running 4.4.4). In hindsight, I can’t ever recall any issues on Android 7.0, mostly on Android 4.x devices.
If it is an issue related to older Android versions, I hope a resolution can be found, short of locking out those versions, as it is still very handy to utilise older devices with Blynk.