Snippets aren't always available in lemma statements

[varkor]

Following the advice in https://github.com/siegebell/vscoq/wiki/Latex-Snippets, the snippets are not always available after, for example, the Lemma keyword. I can't tell where this problem stems — it might not be vscoq-specific...

I'm having a hard time figuring out what conditions cause this, because it's not always reproducible, but perhaps someone else will have an idea.