Database collections enteries missing

I have a database of applications. I have had a few versions of this database because of some added fields and the fact that I wanted the fields in a certain order. Since I started the new database I have noticed that some entries that were in the original are not in either the first or the second. All I did was download the CSV and Re-upload it.
I know the entries are missing because I restored all the databases and I have tiggered on submission send grid emails to prove it. Has anyone experienced this before? It is causing major problems for me because there are people who have applied and been accepted and now have to be put on a waitlist.

Can anyone help?

Hello, @elizabethjhay

Is missing data present in the exported *.csv ? Is the issue reproducible every time you do export/impor?
Please, provide the link to your web site, so authorized Wix personnel can take a look at it.