When typing a command in a command block with the 'command input' box maximized and attempting to use autocomplete, the first autocomplete option is skipped.

Steps to Reproduce:

1. Start typing a command in the chat, for example: "/setblock ~ ~ ~ ".
   Press tab to autocomplete the first option.
   The first autocomplete option is 'acacia_button'.
2. Open a command block (without maximizing the 'command input' box) and start typing the same command. 
   The first autocomplete option is 'acacia_button'.
3. Click the '+' button to maximize the 'command input' box and start typing the same command.
   The first autocomplete option is 'acacia_door.' 'acacia_button' was skipped.
4. Input shift+tab to tab back to a previous autocomplete option.
   'yellow wool' is inputted, skipping 'acacia_button'.

Expected Result:

Autocomplete behavior should not change in a maximized 'command input' box.

Additional Examples:

Type into a maximized 'command input' box:

/effect @s res

• Press tab to autocomplete 'resistance'.
  'fire_resistance' is autocompleted instead.

/fill ~ ~1 ~ ~ ~2 ~ reds

• Press tab to autocomplete 'redstone_block'.
  'redstone_lamp' is autocompleted instead.

/give @s iron_bl

• Press tab to autocomplete 'iron_block'.
  'raw_iron_block' is autocompleted instead.

/fill ~ ~ ~ ~4 ~4 ~4 stone o

• Press tab to autocomplete 'outline'.
  'destroy' is autocompleted instead.

Note: If there is only one autocomplete option, it will work correctly:

/give @s point

• Press tab to autocomplete 'pointed_dripstone'.
  It works properly because 'pointed_dripstone' was the only option.