When you click buy FT go to the market and try to place your order, if there are no sellers or the price they quote is not competitive you’ll get an order rejected. This only happens with small caps & volatile stocks.
If anyone would like to vote for a solution this is the best suggestion. When you click buy FT show you what price they can achieve and you get to accept or decline that offer. I don’t know if it’s technically possible on the platform they’ve build but this is the thread.