As you know, when we define a style for an element in the hover status, after leaving the hover status settings, the style of the element returns to the default state. But if the desired element has a class, this will not happen and after leaving the hover settings, the style of the element will still remain in hover status. except by reloading the builder, or using reload canvas.
I was able to reproduce the error and I added it to the internal bug tracker.
Now, you mentioned that this goes away only if the user refreshes the builder, but in my testing, if also went away if you clicked outside of the button or/and went with the mouse over it. It may be faster than refreshing builder.