I try to use the Roon web display on my Samsung Tablet, I only see the Roon logo screen on in Dolphin. But it works on Firefox with the same setup.
Seems Roon cannot connect to Dolphin properly. Would like Roon can also support to Dolphin. If there is a new request, please advise how can I proceed this requisition.
Seems it can press F11 or Ctrl+F11 to enable the full screen mode, however I do not know how Tablet to launch a keyboard app and then show it on screen?
I don’t use Firefox on Android and I also don’t have devices still running Android 4.4 so I guess you have to figure out yourself if there is a working solution for you – can’t do more for you as I already did here (hint blue text is a clickable hyperlink).
Alternatives: Try Chrome or other browsers; get yourself a device with newer Android (preferably one that is able to run Roon Remote also).