If you drag your Opening Hours to be the same as the closing hours, especially all the way to the right (24:00-24:00), the sliders get stuck together. I was finally able to separate them again, but it took some convincing. (I had to click on the bar itself, not the radio button). I believe the far right radio button (closing hours) is defaulting on top of the left one (opening hours), making it so you can’t click the opening hour radio and slide it back to the left.
Thank you for the report. I have transferred it to Github: Opening hours sliders don't work anymore when start and end are both set to 24:00 · Issue #442 · hovgaardgames/bigambitions-public · GitHub
Has been fixed a while ago, closing here.