VS cannot specify "only <enter>" in the "Commit completition list by typing" option

[cpyrgas]

The setting "XSharp\Intellisence\Commit completition list by typing ..." is not saved if you specify an empty line in the input field. After restarting VS 2019, this setting restores the default value:

{}.,:;+-*/%&|^!~=<>?@#'"\

I need autocompletition from combobox only by explicitly selecting an item and pressing Enter. To do this, I deleted all the characters in the above setting. But after restarting VS 2019, the setting is restored. At the same time, the completion is still performed on some characters (for example, the closing bracket), even if not a single character is specified. If I specify any useless character in this setting, then input completion works correctly (only by Enter).