Typically, this issue only occurs when the internet connection is limited or restricted in some way. Please follow these troubleshooting steps to help resolve the issue:
Try uploading the photo from an alternate device. For example, if you are using a laptop, switch to your mobile device.
If you are currently using a device connected to Wi-Fi, try switching to your mobile device connected to cellular data and retry the upload. If you are already on your mobile device using Wi-Fi, just try switching to cellular data and retry the upload.