Option 1: from settings
You need to disable the Javascript Language Service by going to Settings> Text Editor> JavaScript / TypeScript> Language Service and uncheck "Enable a new JavaScript language service"

Option 2: disable it through the registry
[HKEY_CURRENT_USER \ SOFTWARE \ Microsoft \ VisualStudio \ 15.0 \ TypeScriptLanguageService]
Create / Modify dword UseTypeScriptExperimental to 00000000
"UseTypeScriptExperimental" = DWORD: 00000000
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