Bug or feature (v. 3.94)

With version 3.9.3, the bootstrap slider icon for previous/next buttons was a large disc with symbols inside pointing left or right:

(<) and (>)

Now with version 3.9.4, the icon is much smaller, just a small circle with no other styling – so left & right side symbols are the same.

Is this an intentional change of slider styling?

Or is there a glitch preventing display of an element?

I did clear all caches before viewing the slider to eliminate possible style conflicts. I have modified display of other elements in my slider, but nothing that should affect the basic shape and side of these buttons.

The page I need help with: [log in to see the link]