I have the same problem with my Giant team. I believe it is due to the team having more than three bonuses applied to it.
If you want to remove someone from the team, you can recruit another troop and replace someone on the team. Example: Recruit Tyri from the troop menu and replace Jarl. Once the team has only three bonuses again, everything is back to normal. It’s not a fix, but it allows you to work around the bug.
Has anyone had the issue upon activating bone dragon’s spell, where they’re unable to select which troop’s armour they want to strip? It’s happened to my girlfriend and I quite a lot of times. You cast it and you try to select the troop and it just goes off, (in your hands so to speak! Lol), this is extremely annoying when a troop already has little to no armour and others have 20-30+