I'm sorry for late reply.
I didn't understand your question clearly. I have a few questions for you.
1. Does it mean that your RS150b is not being searched by the RoseConnect app? If so, do the IP addresses below appear the same? RS150b: Settings–>System info–>IP Address
Phone: RoseConnect Premium app–>RoseConnect IP
2. Does it mean that RS150b cannot be searched for music on apps such as Rose Tube, Qobuz, and Tidal? If so, please factory reset the RS150b. RS150b-->Settings-->System settings-->Factory reset
Why my Rose 150B 's search function cannot work suddenly ? Anyone can help ?