Purchased a 2025 outback 2.4l turbo. Now have 1100 miles and have noticed when i set the cruise at 65mph on a flat road the rpms go from 1900 up to 2300 and then back down every 10 seconds. It is almost like the trans is slipping. This up and down does not happen when set at 60mph or at least not noticable on rpm gauge. Is this normal?