I'm running LE 9.2.1 on RPi 4 4GB and just installed your plugin, it seems to work flawlessly! Thank you so much, this finally got my so to use kodi for her music playback 
I'm also using a VPN to connect to my parents where I have my media server running (emby) and this doesn't seem to interfere with discoverability of spotify connect on my local network. (But I'm not explicitly routing all network traffic over that vpn)