Photoshop Express on iPad reduces image file size after export

Hello There, This is a late reply to this post, however did you ever manage to resolve the issue with downloading the uncompromised file? I am still facing the same issue, all my images are downloaded at 40% of original image size after using PS Express on iPad Pro M4. I have tried all the usual steps, including reinstalling app,  maximizing the save quality, clearing cache etc. however any image for example 30MB will be around 12MB after using PS Express. This 60% reduction has been consistent across all my images and I just cant find a way to avoid this loss in image.