XC90: 11-speed automatic?

Hello, I roll down a mountain in the 4th gear. I want to slow down my moose a little bit and switch back a gear. The indicator jumps to “3” and the speed goes up (e.g. to 2300). After a few seconds, however, another switch seems to take place: the indicator remains (of course) to “3”, but the speed goes up again (e.g. to 2600). This also occurs with other gears. So with these “intermediate gears” my GT has 11 gears But seriously: What does the GT d a? Why this switch-over? (With the lock-up the m.E. has nothing to do with it, or does it start so quickly?) Relevant information receives as always gratefully: xc90er …who wants to expand his modest moose knowledge again.