Shared Ownership Mortgage

Still_learning

Hi guys, looking for a bit of advice, I'm  looking to purchase a shared ownership property and wondered if anyone had any recommendations on a  specialist shared ownership broker. I've looked at the lending criteria's for both high street lenders like Halifax, Barclays, Tsb and nationwide as well as smaller building societies. I have no CCJs or defaults, but a few late payments on old credit cards from 2019 which have since been settled and cleared early 2020. I have no other outstanding debts, but do have an existing shared ownership mortgage which is all up to date have the odd one late payment marker in 2019 but have been update otherwise. I was hoping to get 5% deposit on the share I wanted to buy on a two year fixed rate with the view of being able to buy the full property after that, but high street seem to want you to put 10-15% down and you can get a rate around the 2% mark, but the building societies like Leeds, Newbury, Kent reliance etc will do the 5% deposit but interest rates are between 3.29% and 5%. Really like to speak to a specialist broker or hear about anyone else's experiences as the brokers I have spoken to don't seem as clued up about shared ownership and or the lending criteria's. Any advice would greatly appreciated. The original broker I used completely disappeared so cant use him.