Im using sonar and radarr with deluge så the autodownload is working.. But i cant remove any torrents because i cant se them in webui

My guess is maybe that i have to many torrents thats causing problems. Have around 1000
How do i manually delete them?
Any tips and trix is appreciated
Setup:
Deluge running on Synology DiskStation DS918+
Deluge version: 1.3.15-8
DSM Version: DSM 6.1.6-15266 Update 1