Written to help members who may have same issue.
I’ve just identified an issue when using CE as a renderer to stream files from my
Android Phone.
Using BubbleUpNP APK on my phone , my TX3 Mini was not showing up as a renderer on my Network.
I used Fing APK and the TX3 Mini was showing up BUT no UpNP service in Kodi Services.
Through trial and error I discovered that with a WiFi USB Adapter , I had to go into CoreELEC Settings and activate Wait for Network before starting Kodi , then reboot.
UpNP was then available. SOLVED.
This only happens with Wifi .
Does not happen with Ethernet which i use 90% of the time.