make sure to set the leader in the beginning

init.lua

@@ -1,3 +1,4 @@
+vim.g.mapleader = ','
 require('my_plugins')
 require('my_keymappings')
 require('my_options')

lua/my_keymappings.lua

@@ -1,4 +1,3 @@
-vim.g.mapleader = ','
 local opts = { noremap = true, silent = true }
 vim.keymap.set('n', '<space>', 'nil', opts)