The HUD disappears

[Foyr]

I have a big problem! Often, but not always when I'm in combat, the HUD on a random hero disappears and freezes me completely from combat, so much so that I can't skip the turn anymore. It can't happen while I've been fighting a bunch of monsters for a while, and I don't know if it's a bug or something. did it just happen to me? or even to someone else? If yes, do you know how to fix it? it's really a pain to reload your last save and lose an hour of combat for nothing.