What you were expecting to happen, and what actually happened:
Team Bonus for having 3 or 4 Boss troops in the team is missing. Also the titile “Boss General” and “Boss Capitan” is dispalyed as variable.
How often does this happen? When did it begin happening?
All the time
Steps to make it happen again
Create a team with 3 or 4 Boss troops, click on any troop and check Team Bonuses for this team.
as far as I understand it, boss is another rarity, like legendary & mythic, not a troop type. rarities don’t have bonuses set in teams, e.g. there is no bonus set for having 4 mythic troops as well. Only troop types have the “x General” bonus applied.
So it appears to me that having a boss troop bonus is neither intended nor expected behaviour.