I'm betting on one of two things.
First, remove the nib, front section and converter, as one unit.
Look for ink stains where the feed (little ridges under the nib) meets the converter. If there are ink stains there it indicates a faulty seal between the converter and front section. If there is ink there, remove the converter. clean the entire assembly and replace the converter with an international cartridge. If the leak stops, the problem was the converter. If the leak continues, and there is ink stains where the feed meets the cartridge, the problem is a defective "front section".
If there is NO ink stain where the cartridge/converter meets the feed and the ink is still leaking, the problem is with the nib/feed assembly. WITH THE TRITON, it is absolutely ESSENTIAL that the feed be (horizontally) centered on the nib. Most of the time, this can be corrected simply by unscrewing the nib and feed from the front section and realigning the nib. At this point, check carefully that the nib was not bent from shipping or assembly.
I hope this helps! A Triton FP with a Heritance nib is my favorite writing instrument.