I have difficulty understanding the construction of ZDD from SNF.

As I understand, given an FDD, to get a ZDD the steps are:

1. Set representation of FDD

2. RMNF form of the set representation

3. Construct SNF form

4. Draw the tree from SNF

Correct me if I am wrong.

So, when I do it for the question:

I get the set representation {{a,b,c}, {b}, {}}

which leads to RMNF of a&b&c ^ b ^ true

For the same, I get the SNF as in this picture.

But the ZDD constructed for the same, does not match with the solution:

What am I doing wrong?

PS: I also tried constructing a truth table and then from the DNF getting SNF which leads to the same SNF but the ZDD does not match.

Edit: I have also done the DNF and then constructed the tree.

Is there a different way to get the ZDD from set representation? Because I got the truth table right which in turn gives the set representation {{}, {c}, {a}, {a,c}, {a,b,c}} but when I convert it into full DNF like below and then get SNF for it and draw it, it is different from the solution.

I gave it a lot of time, not able to figure out what went wrong!

Getting SNF for DNF using set representation

Drawing the SNF (Which is supposed to be ZDD?):