Connection is closed with preview when I switch the buffer.

I am using `LunarVim`, `bufferline` and `nvimtree`.

When I switch the buffer on `bufferline` or open new buffer on `nvimtree`, the connection between the preview web page and the buffer is closed. Even the markdown buffer is still opened.

I have tried `vim.g.mkdp_auto_close = 0`, it indeed did not close the web page but the connection is still closed. I meant by the connection, no iteraction after it is `closed` whatsoever, so I have to open new preview.

Was this on intention? Or if it is not, can I make it to not close the connection? It seems there is no config for that.