Well, I managed to finish my campaign without having the problem again (your game is awesome btw).
I'll continue to keep OBS in the background as I play, but the problem has a very low reproduction rate, that's for sure.

I'll keep OBS recording in the background with my inputs displayed while I play, hopefully I'll be able to send you a video soon so you can get an idea!
And I'll also try to find the reproduction steps, of course.

So from time to time I've noticed that I manage to prevent the game from zooming in/out with the mouse wheel.
I don't know how I caused this bug but I know that scrolling in a window like the battle report allows me to zoom in/out again so I guess I triggered it by zooming in/out and scrolling in a ...