So just so I understand...

1. I redeemed 2 king rooms at 60,000 x 4 = 240,000 each.
2. The system immediately pulled the points at time of booking.
3. The system did NOT pull the certificates at that time.
4. I called the hotel and made arrangements to change one of the rooms to two doubles and agreed to a cash upgrade as these were not available as points. This was done the day the points booking for the king rooms were made.
5. Months later the system pulled certificates and this caused an additional 100,000 points (85,000 x 4 rather than 60,000 x 4).
6. Why did this happen on one of the rooms (the 2 doubles) but not both rooms?

I got the 100,000 back but am still confused.