Autocomplete for sfc.vue with vls does not work on template section

[maxim-usikov]

Information

VIM version VIM - Vi IMproved 8.1 (2018 May 18, compiled Aug 3 2019 18:05:22) macOS version

Operating System: macOS Mojave 10.14.5

What went wrong

Autocomplete for template section does not work.

Reproducing the bug

1. Open any sfc vue file.
2. Try to autocomplete some vue attributes on tag (v-for, v-bind, ...)

:ALEInfo

 Current Filetype: vue
Available Linters: ['vls', 'eslint', 'fecs', 'flow', 'flow-language-server', 'jscs', 'jshint', 'standard', 'tsserver', 'xo']
  Enabled Linters: ['vls']
 Suggested Fixers: 
  'prettier' - Apply prettier to a file.
  '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_vue_vls_executable = 'vls'
let g:ale_vue_vls_use_global = 1
 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 = 100
let g:ale_completion_enabled = 1
let g:ale_completion_max_suggestions = 50
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 = {'vue': ['vls']}
let g:ale_linters_explicit = 0
let g:ale_list_vertical = 0
let g:ale_list_window_size = 10
let g:ale_loclist_msg_format = '%code: %%s'
let g:ale_lsp_root = {}
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_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_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
 LSP Error Messages:

(Errors for vls)
Request textDocument/completion failed with message: Cannot read property 'completion' of undefined
  Command History:

(executable check - success) vls
(started) ['sh', '-c', '''vls'' --stdio']

[w0rp]

I think this might be an issue with vls.