I’d wait and see. While your waiting, check around the base of the plant to make sure you haven’t buried the trunk too deep when planting or that you’ve piled mulch up against the trunk. Doing either of these things slowly strangles the plant, causing the symptom you’ve described and will eventually kill it. Brush any mulch and dirt away from the stem until you find the original soil that the plant came in. Let the bark breathe!!!