Due to unusual malfunction on my ISP side (no access to Google servers, including DNS 8.8.8.8 and all popular services like Search, YouTube, Maps, etc.), I've discovered an area for probable improvement of KDE Connect's great solution.

With ISP's “block” of Google, my phone recognized my home Wi-Fi network as “connected, no Internet access”. This dependency on Google is obviously Android's issue, but it caused KDE Connect to lose connection to Linux/KDE Plasma. The local network itself was uninterrupted — both Android phone, and GNU/Linux computer could ping each other from the terminal just fine.

I assume KDE Connect's solution doesn't really depend on public Internet access, yet Android app seems to require it.

STEPS TO REPRODUCE
1. Unplug cable from ISP in the router / disable WAN on the router.
2. Android device stays connected to the router by Wi-Fi, but informs of “no Internet access”.
3. Lose KDE Connect's Android<>GNU/Linux link.

EXPECTED RESULT

Don't care about public Internet access as long the device is connected to the network.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 37
KDE Plasma Version: 5.27.6
KDE Frameworks Version: 5.108.0
Qt Version: 5.15.9

Android: CrDroid 7 (based on LineageOS based on Android 11)
Android's KDE Connect: 1.27.1 (F-droid version)