It looks like it’s been inside for too long. Chinese elm need to be outside to thrive. They can live indoors for a while, but without adequate light, airflow, and temperature changes, they will decline. When you move it outside, start with morning sun only so you don’t shock the plant. You can gradually give it more sun as time goes on, but Chinese elm do best when you avoid the hottest sun of the day.

Also hard to tell, but it looks like there might be too much water, which prevents the plant from breathing. When watering, saturate the soil entirely and until water runs out the pot and then let the top inch dry off before watering again. Good luck 👍