Ideas
I have been playing with werewolves recently quite a lot. My game is up to date and I have every single DLC installed.
I had this issue in the past where werewolves would get to Apex rank and then the xp bar would not checked once reaching the end and I would not get any points.
Today, it's different, when my werewolves get to Apex rank, upon getting another xp point, they not only dont get any point, but it reset the rank to Veteran second tier... with the point(s) used in the Apex rank reset. You can still use those points, but I also did not get any point. Now I tried moving up rank again, and it worked, I got to once more, Apex, but again, no points allocated for passing to another rank... the whole thing is bugged, but I had to play several weeks in game with that same family to have this triggered. I have played with this family quite recently after the last patch, so I don't know exactly what triggered the bug to occur.
I play in Moonwood Mill, with Kristopher Volkov and his new wife, which is also a werewolf and was transformed by Kristopher. I had no issue with Kristopher getting points being an Apex while she progressed, until she got to the Apex rank and then both started to have their rank reset to Veteran and again Apex, Veteran, Apex, without getting any new xp. They also have 3 horses. Now that I am thinking, there have been lots of thing happening at the same time, but they got the riding skill maxed out and I think after that it started to happen...