Photos Disappearing

We have added photos to a webpage and been back to add extra things and the photos are gone. We sometimes have to re-add them or other times they show up again. We have published pages with photos and only some photos show up.. It has only started happening recently with Adobe Express. It is very frustrating. We started off using Spark for our school website and this didn't happen. It only seems to happen lately with the update of Express. I have seen chat forums mention this issue.