There are a couple of ways you can fix this problem. The problem is Intellisense is getting in the way or default putting your snippets at the bottom of the list.
First I played with the suggestion delay, but then I settled on having Intellisense put my snippets in the top of the list of suggestions with the snippetSuggestions user preference:
{
"editor.tabCompletion": "onlySnippets",
"editor.snippetSuggestions": "top"
}