once I uploaded the theme some of product images didn’t load also when i tried to upload images again appear an error ( The server cannot process the image. This can happen if the server is busy or does not have enough resources to complete the task. Uploading a smaller image may help. Suggested maximum size is 2560 pixels.)
although the images do not exceed 2000 pixels, also i contacted with hosting support team and they confirmed that the main problem from the theme or a plugin.