Typing a period in a comment in nvim causes NO_RESULT_CALLBACK_FOUND error

[realh]

Describe the bug
If I'm editing a comment in neovim and press period (.) in insert mode I get this error:

LSP[vala_ls]: Error NO_RESULT_CALLBACK_FOUND: {
  id = 21,
  jsonrpc = "2.0",
  result = {}
}
Press ENTER or type command to continue

I've only just started to use vala so I don't know whether this bug is present in earlier versions of anything.

Software
OS and version (e.g. Ubuntu 20.04): MacOS 15.6.1
Code editor (e.g. VSCode): neovim 0.11.4
Vala Language Server (e.g. git commit, or PPA/AUR version): 0.48.7 (homebrew)
Vala version (valac --version): 0.56.18

To Reproduce
It's difficult to give a step-by-step guide to reproduce this because nvim config is very complex and flexible. I'm using the lspconfig plugin and I haven't passed any additional options to its vala setup.