Issue with editing image or thumbnail for characters

[Arctaxia]

Steps to reproduce:

1. On a character that was already uploaded, click Edit Submission File
2. Upload the new image, then click Reupload File
3. The old image remains and the thumbnail seemingly disappears on profile and elsewhere. However, when going to Edit Character Thumbnail after re-uploading, the new image is shown as a preview.

Re-uploading character thumbnails is similarly bugged. I've tried this on both Firefox and Chromium and cleared my browser cache, and the same thing happens.

[charmander]

Character thumbnails are also cached at the CDN level for up to a week. That’s probably… too long.