No, this is usual behavior.
I suppose that you’ve installed kak-lsp by manually cloning the repo, and then added the plug.kak config for it. That’s not the proper way how to install plugins with plug.kak. Because if you install it via plug-install it will run post-install hooks, which are compilation and installation (if specified). So there’s no need to place a symbolic link in your /usr/local/bin, instead, you should check where cargo installs kak-lsp and add this folder to $PATH.
My recommendation would be: do :plug-list, move cursor to kak-lsp plugin in the list and press D – this will delete plugin. Next press I or Return – this will install kak-lsp and post install hooks will be executed. Wait until it is compiled and installed (you’ll see the done message), and press L. Installation log will be opened. At the bottom you’ll see where cargo had installed kak-lsp. Add this path to your $PATH.