Hi folks

Just looking to talk some strategy about 4bet calls from various positions. I bought GTO+ a month ago and have been messing around with it since then, but only recently took a look at GTO-Wizard. Plugged in some 4bet spots, noticed that it is calling more often with 99 than with TT in some spots and already I am very confused. Can someone explain why this is?

Also, in terms of more exploitatively, how do you construct your 4bet calling range? Particularly on RIO I tend to play exploitatively, because I know they can't collect stats. I 4bet bluff disproportionately with A5s, for example. In the RIO context, are you happy always folding hands like ATs to a 4bet? Do you mix in some flats with KK in position? Curious to hear your thoughts. Thanks.