Dropbox is a cloud storage service operated by Dropbox, Inc., headquartered in San Francisco, California, US. Piktures is NOT associated with Dropbox.
Piktures is able to manage, view, upload to, and download photos from Dropbox.
To do this, Piktures uses the Dropbox Android SDK.
With the Prime and Premium version, you also have a Back-up option.
If you have refresh issues, please remote your Dropbox access, and add it back.
This should restart the process and all your refresh issues should be gone.