My .png files are being converted to .jpg without transparent backgrounds on my iPad

I updated my iPad to iOS 13.3 overnight and this morning, I finished a commission in Procreate. I went to send it to the customer and every time I saved it, the file was converted to a .jpg file and given a white background. I did google searches and didn't find a solution; I am not using iCloud Photo Library, so they're not being optimized. And in my settings, I have it set so my photos will keep their originals. That didn't help either. I've also noticed that all of my previously saved images have been converted. This is enormously frustrating, since my iPad is almost exclusively an art tool and the majority of my work involves saving my images with transparent backgrounds.

I was able to eventually get the file to my customer by air dropping it straight from Procreate to my laptop, but that doesn't help the last 3 years' worth of files that have suddenly been converted.

Is there a way to change my files back? My art is both my income and my relaxation and this is really going to impact my ability to share my work.