hi there, I know it’s an old thread, but if anyone is still having issues with this, I managed to downgrade my ue boom (1st version) to 1.4.50. This was the farthest back I could find that worked, I think mid 2015. I am using my boom as an airport express - attached speaker for airplay 2. So I don’t care about the bluetooth functionality or needing it to work with the app or other ue booms. Downgrading completely fixed my delay and now my boom is in perfect sync with my HomePod and other speakers. You’ll need a PC to do it. I found the firmware on website below. If you can’t find firmware send me a PM and i’ll try help. https://www.touslesdrivers.com/index.php...