How to reproduce on v3.19:  

1- From Transfers tab, click on the gear icon.  
2- Click on Transfers > Files.  
3- Enable Skip last-write time checks.
4- Remove a fully or partially downloaded torrent from Tixati Transfers list.  
5- Add that torrent again, and choose the same location where the files were previously downloaded.

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Tested on Windows 7. File allocation: Sparse (default)