So I've finally been trying the beta, and I've run into this issue that fairly often, my starting hero is missing spells.  He'll get a handful of basic spells (that seem generic to all sovereigns from what I've seen), but not get any of the sphere ones he should have, such as one with Fire 2 and Life 2 not getting heal, regen, or ANY fire spells at all.

I've not figured out what causes it, and with some games he'll get his full spell allotment, but once I start getting that bug, I KEEP getting it until I delete all custom heroes AND restart the computer, and even after that I can still get stuck with it.

For what it's worth, this happens with custom heroes.  I haven't used any of the pre-made ones, so I can't tell you if it happens with them as well.

I have noticed that immediately before this happens, one custom character gets all his options cleared, his gear resets to defaults, and his head vanishes from his picture.  Deleting and remaking the character restores that, but doesn't help with the missing spells issue that follows it.  (If I use the same name afterward, the next game starts with every unit I've ever made with him in prior games available, but with no armor or weapons.)