Figma Sites Auto Layout not working

Hi,

I’m exploring Figma Sites for the first time and doing everything step by step to better understand how it works. I created a simple frame with text on the left and an image on the right, using auto layout throughout. However, when I copy it into Sites, select my frame, and set the auto layout property to “Fill container,” it doesn’t work — the element doesn’t resize as expected. I followed the exact same steps shown in the YouTube tutorial, but my file doesn’t behave the same way. Could you help me figure out what’s wrong with my file?