I tested playing music to my Fire Stick (first gen, very old by now) and had no problem with v3.6.10.
I suppose the grey "wave form" you mention is the loading animation (5 grey bars moving as a wave), meaning that if they remain
for a while, the Fire Stick cannot stream from BubbleUPnP for some reason.
So I can have a look, can you send me (at
bubblesof...@gmail.com) a log file recorded on the problematic phone, attempting to play on your Fire Stick a media that fails to play:
- launch the app
- go into More > Gear icon > Control
- Enable "logging to file" (at the end of the page).
- IMPORTANT: Exit the app (More > "X" bottom left icon)
- restart the app
- attempt to play on your Fire Stick a media that fails to play. Let the loading animation on the FireTV display for a while (say, up to 1 minute)
- exit the app
- email me the files found on internal storage:
On Android 10 and below:
/Android/data/com.bubblesoft.android.bubbleupnp/log.txt
/Android/data/com.bubblesoft.android.bubbleupnp/prev_log.txt (if present)
On Android 11 and higher:
/Downloads/com.bubblesoft.android.bubbleupnp_log.txt
/Downloads/prev_com.bubblesoft.android.bubbleupnp_log.txt (if present)
You can access them with a file manager app and share them to your email app for sending them.
IMPORTANT: Make sure to not restart BubbleUPnP until you have sent or saved the log file as it is overwritten on app startup.