First Wife does not have her husband as ally, other wives do

[Tintiam]

I've noticed if a character with a polygamous religion has wives who are rulers, the first wife does not have her husband as an ally.

The husband has all four wives (if all four are rulers) as allies. The secondary wives all have their husband as ally. It's only the first wife that does not have this honor.

For quick clarification purposes I used console commands to marry some women to the caliph to show this possible bug :

Husband has both wives as allies:

First wife has no allies:

Secondary wife has husband as ally:

 

[Tintiam]

Just tried the same thing out in 2.5.1 and it's still there. First wife does not have husband as ally. Other wives do. Husband has all wives as allies.