I found another bug.  I got the 2 traits that reduce the leader cost by 50% together and make 1 more available.  Unfortunately it only says its gonna give me, although I dont know if it does or not, the 50% off when I select the leader through the leader screen and not the planetary main screen where I select a planet and see the region map and go to pick a governer to make it a core world.

specs

epic game store gal civ 4 base version 2.3

windows 10, 16gb ddr4, ryzen 3600, rtx 3050