Data lost when I changed questions on my form

Hi, a few weeks ago I amended some questions on my project form which then updated on my phone. However when trying to download the data recorded on the previous form all I get is a blank space. It looks like the data and photos on the old form have been deleted. Is this correct? I hope not. Any ideas? Thanks.

Hi, if you deleted any questions, the data linked to those questions got deleted as well.