I used the latest opt-in build to test and verify that it works.
It works FOR YOU. I learned early in my thirty seven years of developing software that "It works here" is not the end of diagnosing a problem, it's a point of reference where comparisons of the differences in the environments can lead to a discovery of the real problem. Hence my asking if using a different leader portrait/race icon could cause it.
I am, I think, the second person to report this; the first was mentioned in a post with multiple other points and a title not referencing this problem, hence I can't find it.
Anyway, if you would like to examine the custom race I used to see if anything was done that could have caused a problem, I submitted a save from that game for a different problem early today, in ticket #RME-280-14194.