Running kdeconnect in an emulator
The android emulator uses the default qemu User Networking (SLIRP) backend which does not allow the emulator to be directly accessible from the host nor the local network, which prevents kdeconnect running on the desktop from seeing kdeconnect running in an emulator. In order to get a fully working network in the emulator it needs to be configured to use the tap networking backend which as an added bonus offers much better performance than the default user backend.
Running the emulator with the tap backend will create a virtual network device on the host machine that can than be configured as if it is a real ethernet card allowing you to create virtually any type of network topology. The most straightforward topology that can be created is the public bridge setup. In this setup we simply put both the emulators virtual interface and the desktops lan interface into a bridge so they will share the same network space (e.g. single IP-subnet). Another topology that can be used is the Routing with iptables setup this involves a little more work but will work in situations where your lan device does not support bridging (eg. some wireless drivers)
The public bridge setup