Fannie Mae...Ever had this happen???

Made an offer on a Fannie Mae home and they countered with a pretty decent offer but added a clause that we couldn’t sell within a 90 day window and make more than 10% on it… after 90 days we are free to sell and make what ever profit we want…

Ever heard of this? we made a counter offer and included a change to 60 days…

Anyone have experience with Fannie Mae? Is this usual for them?