[Affinity Photo on iPad wasting disk space?]

I have the same problem, my file size was 6 gb and it went down once I closed the files I was working on, and they were regular sized files (most of them 20 megs), this happened using a first generation ipad pro. I don't know why this is happening, all the work files I got on Affinity Designer  add up to around 300 megs. Please help, we love using Affinity design and Affinity photo, but this and constant crashes are driving us crazy.