Re-loading the area auto-save and the quick save to try to re-roll drops is considered an exploit and is typically not a permitted topic on the forum. However, given the totality of the matter, it might be helpful to discuss.
Per the Wiki, the impressive
Staff of the Traveler is dropped by the
Ashen Warlords in the Sunken Citadel. There are only two of them in the Citadel.
I don't know what the drop rate is for the Staff at this time, but for ease of math, let's say it has a 5% drop chance. That means for every dungeon run you get two chances at 5% to get the staff., so everyone's favorite binomial calculations come into play:
1) After 5 dungeon runs, you have a 40% chance of getting at least one, and 60% of none.
2) After 25 dungeon runs, you have a 92% chance of getting at least one, and 8% chance of none.
3) After 50 dungeon runs, you have a 99+% chance of getting at least one, and less than 1% chance of failure.
So it's quite possible you are just lucky on this exact item. Luck is random so everyone gets a turn in the yuck bucket sometimes.
The math is discussed
here.