A "grand" time with the robots

Playing with the robots on Bridgebase Online, I held this hand:
♠Q 9 4 ♥A K Q 6 ♦A Q 8 ♣A 9 3.
I was surprised to see my robot partner open 1NT. What would you do? I suppose the proper bid is 5NT, forcing to 6NT and inviting 7NT. Being a little leery about doing that, I bid Gerber, heard partner had the missing ace and bid 7NT.

                ♠ Q 9 4
                ♥ A K Q 6
                ♦ A Q 8
                ♣ A 9 3
==
                ♠ A J 10 2
                ♥ J 8
                ♦ K J 2
                ♣ K Q 10 6

West led the ♠3. South played the 9 and East contributed the 5. If the spade finesse is on, it's easy to make seven, but you have 13 tricks without repeating it if clubs behave (two spades, four hearts, three diamonds and four clubs).

Robot South lead a heart to his jack, another to the ace, then played a diamond to his king and a club to the ace. That's all four suits in his first five cards played. What will he do next? I could barely wait to see.

South continued with the ♣3 to his king. He led the 2♦ to the queen in dummy, and the ♠4 to his ace! What the . . . ???

Next he led the ♦K to the ace and cashed dummy's two good hearts, discarding the ♠J 10 from his hand. On the last heart East discarded a club, so the jack had to drop now, claiming seven. Here are all four hands (rotated):

                ♠ Q 9 4
                ♥ A K Q 6
                ♦ A Q 8
                ♣ A 9 3
♠ K 7 6 3                      ♠ 8 5
♥ 10 7 5 4                     ♥ 9 3 2
♦ 10 7 5                       ♦ 9 6 4 3
♣ 8 2                          ♣ J 7 5 4
                ♠ A J 10 2
                ♥ J 8
                ♦ K J 2
                ♣ K Q 10 6

Some comments:
1. Why would you lead from a king against 7NT. That's ridiculous. They surely can be programmed better than that.
2. Wouldn't you play the ♠Q at trick one and tempt East to cover? It costs nothing.
3. On the last heart, East had the 13th diamond which he could have discarded instead of a club.

I checked and found that only one other person bid and made 7NT and he dupliated my auction. I also saw, however, that 10 players went set. Why? They bid 1NT 7NT without going through Gerber. In all 10 cases, the West robot lead a heart! I'm not sure why the different auction "tells" him in his simulations to make a different lead. Do you?

In 11 cases, players bid only 6NT, certainly reasonable. Six made all 13 tricks. They had a Gerber auction, found out they were off a king and stopped. They got a spade lead. Five players bid 1NT 6NT and did not get a spade lead (??) and made only six.

One player raised 1NT to 3NT. (Yes, his robot partner made it, lol.) He scored an undeserved 43.48%! If you play online enough, you will see everything.

You can see all the results if you click here.