The app I use also to a few files or download high and made some mistakes, I see, and reports these errors (bugs) on their forum or appropriate in the respective stores. And on the edge times: großschnäußig to pull the product into the mud, has never particularly helpful (especially a reviewer);)
And last (not angry 'meant) to whom this app and the service of ownCloud do not like, so it is recommended not to use it. I know without a large research nennesnwerte alternative that should also work well :)
PS: To (say to sync to folders or at certain events to sync the contents of a folder) a correct folder sync setup, I recommend Folder Sync (uses first FolderSync Lite to debug it (use it himself via WebDAV and my ownCloud server)). From Android 4.4 can not write / save to your SD card you (without root).
PPS: About [...] or owncloud.org -> Contribute and then at the bottom right "Support ownCloud Development with bounties" you can also special features that you want from ownCloud submit donations.