Q.LANTANA loosing its leafs.
Why is my Bandana Cherry Sunrise Lantana loosing its leafs?

Leaf drop can be associated with watering issues; too much or too little,
environmental changes, pests and disease.
These links will refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/flowers/lantana/lantana-plants.htm
https://www.gardeningknowhow.com/ornamental/flowers/lantana/lantana-leaf-yellowing.htm
https://www.gardeningknowhow.com/ornamental/flowers/lantana/lantana-leaf-yellowing.htm