UsersGuide https://www.amibroker.com/guide/w_afledit.html says,
You can also type immediately space (for variables) or opening brace (for function) and AmiBroker will auto-complete currently selected word and close the list (Automatic statement completion).
I've tested this on v6.35 beta on Win10,
and found the key [Space] or [Opening brace]
cannot auto-complete currently selected function name,
also the key [Space] cannot auto-complete currently selected built-in variable name.
For example, I want to type ParamDate, so
step1. After type P I can see it appears on the 3rd item on auto-complete listbox.
step2. Use up/down arrow key to select the item ParamDate.
step3. Press [Space] or [Opening brace] cannot auto-complete it.
Although we can use [Tab] or [Enter] to accept the selected item.
but [Space] is the most longest key on keyboard (most easy to touch),
and [Opening brace] is the most meaningful to complete a function name,
so please consider to implement them on development versions.
AmiBroker works perfect. But YOU don't read carefully enough. The user guide says something else that you wrote
The automatic completion feature (available when you press CTRL+SPACE key combination) finishes typing your functions and reserved variables for you, or displays a list of candidates if what you've typed has more than one possible match. You can select the item from the list using up/down arrow keys or your mouse. To accept selection press RETURN (ENTER).
Ctrl+SPACE only brings up the list of available choices. It is the RETURN KEY that accepts the selection, precisely as documented.
In fact if "auto-complete" setting is in "Immediate" mode you don't need to press Ctrl+SPACE at all as the list is brought immediately. It is only needed when relevant setting is "On demand"
If you switch it to "On Demand" then you use Ctrl+SPACE to bring up the list as documented. In "immediate" mode you don't need even that as the list is shown as you type second character.
So, NO, nothing will be changed because it is ALREADY PERFECT.
!