I haven’t read the other replies yet…
My soundcore 2 has the same issue. One time I came back to my office and somone else paired their phone to my speaker. I was unable to repair my phone, even with turning the soundcore on/off. I just turned off my speaker the rest of the day. The next day I was able to repair my phone.
Another issue I have is with the soundcore is when my phone is connected via Bluetooth to my soundcore surge headphones and I power on the soundcore 2, it automatically disconnects my soundbuds and connects to the soundcore speaker, at the same volume I was previously listening to, which is normally loud.
From what I have noticed, the Bluetooth on the soundcore 2 can be very finicky and troublesome to connect/reconnect. I don’t seem to have these issues when using the Soundcore Boost speaker, but also haven’t tried to switch devices on it yet…