Thrawn tells Jorus C'baoth and Captain Pellaeon why he stopped Outbound Flight.

In his novel "Outbound Flight," Timothy Zahn told the story of the expedition known as "Outbound Flight" which was led by Jedi Master Jorus C'baoth - and defeated by Commander Mitth'raw'nuruodo of the Chiss navy, who would later become known a Grand Admiral Thrawn.

In the follow-up novel "Survivor's Quest," also by TImothy Zahn and set many years later, Jedi Master Luke Skywalker and his wife Mara Jade went looking for, and found, the remains of the expedition.

All these events take place in the Star Wars "Legends" universe and are not currently part of the Disney Star Wars canon

On Outbound flight, fifty thousand colonists sailed beyond the edge of the charts. The Republic spent the rest of its existence pretending they had not. 

In the fan fiction video below, the man who stopped them explains why he did so, on the one world in the galaxy where his guest is unable to take vengeance. The conversation takes place on Myrkr, home planet of the creatures in the trees, which are ysalamiri. Each one pushes the Force away from itself, and where their bubbles overlap the effect reinforces until it covers the whole planet. That is why a Jedi Master has no extra powers here.

It's a very well researched piece of work, like the others in this series.