I downloaded ask and bid data for few firms in 2024, I tried in start of 2024 and it was showing missing ask and bid data before 2019. I tried after few months and I was able to get it. I don't know exactly how. Now I am trying to get the data for same firms and same time period as I lost that data but interestingly again its showing missing before 2019. its ask price-trade bid price-trade data from t tick history time and sales. I really need that data now, If I can know what happening and how i can access it.