Bubble UPnP and Yatse not working on GT1-mini

Mounter

Hello!

Have yet anyone successfully operate Bubble UPnP and Yatse apps on GT1-mini?
I have Bubble UPnP app installed on my Tablet as the source of the media files and also on two Android TV Boxes that intended to be the playback devices. My HiMedia Q10 Pro Box is connected via Ethernet to my network and the Bubble app on the Tablet can find it's renderers and working for photos and videos.
But on my other TV Box which is a Beelink GT1-mini (with Android 9, with firware 002P0) that is connected to the same Wi-Fi network as the Tablet, I just simply can't get it to work, as It won't show up in the renderer menu. In this case only the "Local renderer" option is available on both devices.
I don't know exactly what could be wrong or missing just by myself, so I'm asking for some advice. Maybe there is some DLNA app or system component or such similar things/settings that I must look after and try? Maybe also a related issue, that the famous remote controller app of Kodi: "Yatse" seems neither working in the case of this Box as it neither can't find the actual Kodi instance to connect to. It just seems like that something is "blocking" the connection, or some relevant component is missing or switched off in the Android system.  Have browsed a lot regarding the issue, but still couldn't find any clue or solution, so please advise!

Thanks for the replies!