I had to delete and reupload the experiment because it wasn’t syncing from PsychoPy to Pavlovia. I was following these instructions.
I had 28 participants before the deletion and 5 after the fact (we had 4 and just got another participant). I downloaded the data before the deletion. Looking at that file, it is still missing the data. There is no missing data after the deletion.
When I download the data files now, the zip file includes data from before the deletion. So I assume that the data files were not lost when I deleted and reuploaded the experiment.