After further investigation, we find out that this issue is also reproducible with all the "below Search Bar" snippets.
Bug 1575523 Comment 1 Edit History
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After further investigation, we found out that this issue is also reproducible with all the "below Search Bar" snippets. Also, it looks like a regression considering the fact that this issue is not reproducible with the "Special FxA" snippet. However, we have not managed to find a regression window because we've hit Bug 1571441.