ale_floating_preview not working

Question

ale does not popup anything automatically. Neovim 0.5.0, windows 10. I wonder whether I configured ale correctly, since nothing related shown in ALEInfo. in init.vim, mouse=a

let g:ale_open_list = 0
"let g:ale_hover_cursor = 1 " default=1, to show info in echo line
let g:ale_floating_preview = 1
let g:ale_hover_to_floating_preview = 1
"let g:ale_set_balloons = 1
let g:ale_hover_to_preview = 0

Plug 'dense-analysis/ale'

I tried different combinations of these switches, but results were same. Thank you in advance.

1. open a go file
2. place the cursor at a variable
3. place the mouse at another
4. info of variable at cursor shown in echo line. but info of variable at mouse does not show anywhere
5. :ALEHover shows popup=?floating window at cursor

:ALEInfo

 Current Filetype: go
Available Linters: ['bingo', 'gobuild', 'gofmt', 'golangci-lint', 'golint', 'gometalinter', 'gopls', 'gosimple', 'gotype', 'govet', 'golangserver', 'revive', 'staticcheck']
   Linter Aliases:
'gobuild' -> ['go build']
'govet' -> ['go vet']
  Enabled Linters: ['gopls']
  Ignored Linters: []
 Suggested Fixers: 
  'gofmt' - Fix Go files with go fmt.
  'goimports' - Fix Go files imports with goimports.
  'golines' - Fix Go file long lines with golines
  'remove_trailing_lines' - Remove all blank lines at the end of a file.
  'trim_whitespace' - Remove all trailing whitespace characters at the end of every line.
 Linter Variables:

let g:ale_go_go_executable = 'go'
let g:ale_go_golangci_lint_executable = 'golangci-lint'
let g:ale_go_golangci_lint_options = '--enable-all'
let g:ale_go_golangci_lint_package = 0
let g:ale_go_gopls_executable = 'gopls'
let g:ale_go_gopls_init_options = {}
let g:ale_go_gopls_options = '--mode stdio'
let g:ale_go_gopls_use_global = 0
let g:ale_go_langserver_executable = 'go-langserver'
let g:ale_go_langserver_options = ''
 Global Variables:

let g:ale_cache_executable_check_failures = v:null
let g:ale_change_sign_column_color = 0
let g:ale_command_wrapper = ''
let g:ale_completion_delay = v:null
let g:ale_completion_enabled = 0
let g:ale_completion_max_suggestions = v:null
let g:ale_disable_lsp = 0
let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%code: %%s'
let g:ale_echo_msg_info_str = 'Info'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_fix_on_save = 0
let g:ale_fixers = {}
let g:ale_history_enabled = 1
let g:ale_history_log_output = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_filetype_changed = 1
let g:ale_lint_on_insert_leave = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 'normal'
let g:ale_linter_aliases = {}
let g:ale_linters = {'go': ['gopls']}
let g:ale_linters_explicit = 0
let g:ale_linters_ignore = {}
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
let g:ale_max_buffer_history_size = 20
let g:ale_max_signs = -1
let g:ale_maximum_file_size = v:null
let g:ale_open_list = 0
let g:ale_pattern_options = v:null
let g:ale_pattern_options_enabled = v:null
let g:ale_root = {}
let g:ale_set_balloons = 1
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 0
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '>>'
let g:ale_sign_info = '--'
let g:ale_sign_offset = 1000000
let g:ale_sign_style_error = '>>'
let g:ale_sign_style_warning = '--'
let g:ale_sign_warning = '--'
let g:ale_sign_highlight_linenrs = 0
let g:ale_statusline_format = v:null
let g:ale_type_map = {}
let g:ale_use_global_executables = v:null
let g:ale_virtualtext_cursor = 0
let g:ale_warn_about_trailing_blank_lines = 1
let g:ale_warn_about_trailing_whitespace = 1
  Command History:

(executable check - success) gopls
(started) 'cmd /s/c "gopls --mode stdio"'

Answer 1

For errors, g:ale_cursor_detail determines whether the popup shows up automatically or not.

For general :ALEHover information, you have to write your own autocommand:

augroup ale_hover_cursor
  autocmd!
  autocmd CursorHold * ALEHover
augroup END