Dear customer.
Thank you for reaching out here in the Microsoft Community.
In your description, you are using Copilot Pro and the images generated have changed from the original aspect ratio to square. (1:1)
In order to better help you, we need to know some information.
Where are you using Copilot Pro, in the Microsoft 365 app? Or in a browser accessed via a web page? Please let me know.
In our research, we found that the content of the images displayed may not be quite the same in different country regions, so please set your region to USA in Copilot's settings for now. (Some regions do generate square images)
You want to use the aspect ratio of the previous image, you can describe the aspect ratio of the generated image in the narrative of the generated image, for example, requesting to generate an image with an aspect ratio of 16:9.
For images that have already been generated, you can refer to the following steps to try to change them
1 Select (click on) the image you wish to change.
2 Click the function button at the bottom right of the image
3 View the options that appear below the image, they are Square and Landscape, select Landscape
4 View the image to see if the aspect ratio has been changed.
Please try the above options for the image and if there is a problem, please take a screenshot or record a video of what you are experiencing and provide it to me.
I will make further judgment for you based on the results.
Thank you for your understanding and support.
Best regards,
Zev - MSFT | Microsoft Community Support Specialist