Some diagnostics not displayed until file is saved

[Limero]

When using ols in Neovim, some errors are not displayed until the file is saved. Normally, with other LSP clients (like gopls/clangd), just leaving insert mode will always display diagnostics.

Adding invalid code and returning to normal mode without saving:

After saving:

However, some validation seem to happen without saving, like "unused import":

And others:

I see there is configuration setting called "enable_checker_only_saved", but setting that to false doesn't help.