IIIF Preview not updating

[stephenwf]

Sometimes the IIIF Preview does not update.

[glenrobson]

We found the same issue in a workshop I just ran. Instructions for the particpants are here:

https://training.iiif.io/vra-workshop/day-three/digirati-editor/standalone.html

When they first created the manifest and looked at the preview their manifests worked great. When they then went back and edited the label and required statement the updates weren't shown in the preview or the RAW manifest.