For myself, I eventually figured out the problem.
When re-adding the soundbar in smartthings, I got a prompt saying the device was already registered. I hadn't reset it, so that made sense. Smartthings app seemed to suggest resetting it for me so it could be added anew. Great! That's when I started getting stuck at 99%.
As part of the troubleshooting step, I did want to do a proper reset of the soundbar, but couldn't figure out how. I read the manual in two languages, looked through Samsung support pages, spent a lot of time.. only to FINALLY find the answer in a user post.
Which was (for the hw-q96r): While soundbar is on, press settings button (cogwheel) on remote, then press and hold again for at least 10 sec. You'll get a message and the soundbar powers off. Reset complete!
I suspect you need to press and hold setting button as there's something in the display, so perhaps pressing volume (mute) and then holding settings button also works.
Extremely annoying that information like this is so hard to find or even non-existent in Samsung's own documentation.
