Mercenaries are not appearing after recruiting them

When changing mercenaries, the chosen one does not appear in the campaign, even if you press the button to summon them, they do not appear. You have to keep restarting the game for it to work.
Is there a fix planned for this annoying problem?

I have the exact same issue since league release. REALLY annoying. It's random, when you change zone it may, or may not appear. And when you revive them, they may or may not appear. Reserving them and re-hiring them from town doesn't seem to fix it either. It's really annoying and broken. That on top of them one shotting you even when you are almost 10 levels above them is weird AF.