with i2pd I get no errors from tixati but the trackers always time out and the i2pd console shows no sam connection
with the i2p java client tixati errors with "bad i2p session create (51467)" trackers always time out too
ports seem to be correct with both clients

Can confirm, at least on 32-bit Tixati 3.32 on Windows 10. Tested both upgraded client with torrents and portable with clean database.

When enabling I2P, or changing settings, Wireshark shows
> HELLO VERSION MIN=3.1 MAX=3.9
from Tixati to port 7656, then
> HELLO REPLY RESULT=OK VERSION=3.1
in return, then complete silence. You can add I2P trackers, remove them, announce manually, and nothing happens. It's always “Waiting for connect”, then “Waiting for I2P router”, then timeout.

I suspect the interface selection logic. If I manually set the client port in I2P settings to 12345, Tixati says in the log that it listens to 127.0.0.1:12345 for I2P connections, but uses port 58600 to exchange “hellos” with the router. If I clean the port number, it outputs port 58631 in the log, but uses 58632 to send messages. Moreover, interface selection menu doesn't have entry for 127.0.0.1, only for ::1. Choosing it results in “address family not available” error at the next attempt. GUID and interface name seem to do nothing. Or maybe it “works” the same way. I vaguely remember that similar interface and alternative port options seemed to be broken in FOPNU in a similar manner: default (unset) configuration worked, trying to set something manually didn't.

good to know its not just me
I also noticed that turning off i2p doesn't remove the trackers, you have to select all torrents and then tick off i2p in the right click menu