Difference in queuing up as Mid/Top in SOLO vs DUO mode. rito help

im main mid and my friend is main jungle. (he gets jungle 80% of times in both solo and duo...) when i play soloq i get mid lane around 90% of games (without counting role swaping etc. only counting what role the game assigns me). but when i play duoq, im given top in most games. in my last games as duo with him (we queue up as mid/top and jungle/adc), i have 12 times top, 5 times mid and 3 times auttofill. he has 16 times jungle, 3 times adc and one time autofill.

like, we have more chances of queuing up solo trying to get matched in the same game and team with our main roles, than duo.... why is this happening! its frusrating. we want to grind playing mid/jungle. i cant play auttofill top in MOST of our games. this should NOT be happening. first role should always give you the most games. ( or at least 50%! iirc in a riot post some time ago saying regarding mid lane since its the most asked lane, you'll have at least 50% chances for it). RITO HELP