3D Masyu - A Die

Question

Fold this net into a cube and solve this 3D Masyu.
The original Masyu rules apply. In addition, question mark '?' should be replaced by either a black or white circle.

Side note: Yeah, it's almost a die... I'm adding '?' to make sure that the solution is unique. ><

Addendum: Move '?' from the center of side $4$ to the center of side $2$.

Answer 1

By adding a

white circle

we get

Answer 2

Solution

Explanation

When you fold this cube net, you would get this connection:

Start from the obvious one, the two adjacent black cells:

Then some more:

There is a wall in the center since it will form a loop without the lines outside, so the yellow line extends to bottom.

Consider this:
What if you connect the lines below the white cells, in the 6-celled side? (shown in dark green)

So the left one needs to be connected on the black cell.

Now for the question mark:

If it is a black cell, then: So it will be a white cell.

Now, what if you put a horizontal line at the top left white cell, in the side with question mark?

So:

...and lastly: