settlers bosses not spawning

I have had 1 settlers boss spawn in the past month. Being that I am playing SETTLERS LEAGUE I would like a chance to fight the SETTLERS BOSSES. The spawn rate has gotten so bad I never get these bosses. The whole point of playing a league is to have new bosses to kill. What is the point of playing when the spawn rate is so bad you never get a chance to fight them.
I used to get the Admiral when I was able to run three ships all the time. Now every port wants a high amount of crimson iron or orichalcum. I have a lot of everything else but I struggle to get one port done and when it comes up with new requirements it wants more crimson iron and orichalcum....every single port has one or both. So I'm bogged down with that and am not getting the Admiral. I've done a ton of maps and no Black Knight for a over a month. I used to get him once in a while. I have gotten Sason only 1x.

Why is the spawn rate so low, this makes me want to stop playing.

The bosses are just a random chance when doing either ships or atlas runners doing maps, so you don't have to complete those port objectives at all. I know it sucks they get so damn high, they scale based on the level of your current shipping upgrade so if you've maxed out Tujen's shipping then the port quotas get insane requiring like 50,000 crimson iron and so on.

If you just want to see the boss I recommend having 3 teams of like lvl7-8 shippers and sending them on very small shipments, like 100 value. 2 of them should be on those 2 ports that are very close to the town which take about 30 mins each, so you just come back to town every half an hour and send more ships. If you want some free loot I recommend just sending a bit of verisium bars. Like maybe 10 or 20 bars max per shipment, with a small amount of dust if you want. That will get you a nice amount of free scarabs from each one while farming for the boss. And eventually while one of those ships is going they will be attacked by the pirate and you'll get the notification.

I know its rare and its kinda dumb that the end-bosses of this league are tied to rng lol, I always got the pirate when I didn't want him to appear.

Thanks for the tips. Wish they would increase spawn rate, random sucks.