I have an older version and a newer version of Tiaxti.  In the newer version, I don't understand why the maker tried to make something better that is not better.  I have made a dozen downloads in the new version.  Now I have Completed Movies - OK.  Then I have Incomplete, which is the partial downloads-- which is still populated with a lot of movies that have been completely downloaded.  ALL DONE.  Then I have Torrent Drop, where files are suppose to be deleted after loading (per my settings), but the torrents in my folder "Torrent Drop" has the torrents present--torrents that have been completely downloaded. I don't know what torrent clients are coming to.  Let's see, a folder to drop torrents into is OK; a folder of started torrents- OK; a file of finished torrents - still OK; what could be wrong?  Well, the fact that the drop folder of newly added torrents does not empty, and the fold consisting of incomplete downloads does not empty, even after the move has been completely downloaded and then moved to the folder Completed Movies.  In the end, I have a FULL-load of torrent (3 directories full), and a lot of disk space used for the incomplete download that has actually been downloaded, and apparently not moved from Incomplete to Finished, but is a full 2nd copy of the move that have been copied to Completed Movies.  Basically, a chimpanzee could have applied more logic to how this works than the actual program creator has.  So, I'm not going to give you a banana for the new version of Tixati, because you don't deserve a banana for this.

what versions of tixati are you using and what OS?

with v2.86 on linux i do not see the problems you are having.
torrents loaded from a watched folder are deleted when delete after loading is selected.
completed torrents are being moved to completed folder, and not left behind in the download folder.

have you switched any settings recently?