Since v21.04.3 (maybe sooner) uploading images doesn't work if using S3 storage #2739

Describe the bug
We have been using Amazon S3 storage without issues up to version v21.04, last Friday I upgraded to v21.04.3 and we are unable to upload pictures if we use the "Insert an image" option in the editor. Attachments do work if we upload the same image from the Attachments panel. The error is "File path /updates/images/gallery/{image_name} could nto be uploaded to. Ensure it is writable to the server". The same error happens with v21.04.4

Steps To Reproduce
Steps to reproduce the behavior:

1. Go to any document
2. Edit the document
3. Click on "insert an image" and drag and drop an image to upload it
4. See error

Expected behavior
It should upload to Amazon S3

Screenshots

Your Configuration (please complete the following information):

• Exact BookStack Version (Found in settings): v21.04.4
• PHP Version: 8.0.3
• Hosting Method (Nginx/Apache/Docker): Apache

Additional context
Our Amazon S3 bucket is set to public, and also we didn't touch the permissions in a while. I also didn't touch the .env file in a while.