Ranked flex - divisions

Hi! I've been wondering if, when placing us into a division after our 10 placement games in 5v5 and 3v3, is our rank in SoloQ from last season taken into account? One may say it is not logical since it is different type of a Q and you are doing it for the first time but...I was plat 2 in s6 and with score of 6W-4L i got placed in gold 2 in flex q, while my friend, who was gold 3 in soloQ in s6, with score of 5W-5L got placed in bronze 2. So, i don't see any other explanation except our soloQ rank from s6 being taken into account. Am i wrong?

Looking forward to solving this mystery.

P.S. It was probably written somewhere when Riot spoke about flex Q but I missed it..

Thanks! :)