I previously used utorrent and I wanted something different so I switched to Tixati,
I downloaded it and followed the tixati optimization page except I accidentally changed the port so I don't know what port was originally there...
I am using Private Internet Access VPN and I noticed before I was not getting any DHT connection at first but now I finished forwarding the port and such and I download things just fine but they are stuck at 99%....
I am using the port provided by Private Internet Access
I noticed my download speeds are rather slow too, at first they were 1mbs and now it is down to about 75kbs.
Windows 7

My original incoming port settings were;
TCP/udp port for peer connections 25226 (upnp forwarded)
UDP port for dht messages 25226 (upnp forwarded)

Are there seeds with 100%? With peers selected under status are any of the LIs marked in green? Often not all files of a torrent downloaded and only part of the file is available so you need to uncheck the files that are not present. IE samples ,screens or NFO.

Go to Settings -> Network -> Connections

set the protocols to TCP Only. Speeds will go way up.

found this seeing that people in utorrent got speed improvements when they unchecked uTP management.... same happens in tixati if you stop UDP connections.