I am having the same issue with my R1. I can connect with BlueTooth but cannot update the firmware because it won't connect to wifi. never finds the speaker no matter how many times I go through the troubleshooting steps.
I've talked with customer service and they said it's being worked...that was weeks ago! What is the deal...app won't work, speakers won't work, it's all messed up! And no follow up from customer service!
Same issue with Android 10. I have been trying to get support from Samsung's EU department because I live in the Netherlands. After 4 months Samsung is only repeating that the problem is being looked at by the product specialist. I don't believe Samsung is doing the necessary research to solve the issue with the Multiroom App. In the mean time I have a bricked Samsung soundbar in my living room. Unbelievable for a company like Samsung!!