blockchain – why is the block height missing in my transaction?

I use api call to get the transaction details of my incoming and outgoing address. For some addresses, I get block_height and for some addresses, I do not get a block height. Can I know why this problem arises and what will be the reason? Based on block_height, I get a confimation number without block height. I can not make a transaction as confirmed.

this happens with block_height.Please give me a solution to this problem. Thank you in advance.