NFS was mounted at /DATA/library, so the icewhale-files trash regex (^/media/([^/]+)) derived drive=ZimaOS-HD and tried to rename into /media/ZimaOS-HD/.trash on local ext4 -- cross-device EXDEV from NFS. Remounting at /media/library makes 'library' its own /media/<name> segment, so trash resolves to /media/library/.trash on the NFS itself.