Sometimes Saving Sometimes Not

Hello,

I could use some help. I am working on editable pdf files on an iPad mini, the files were created on an iMac. I have had no problems for a long time until recently, and now I am having problems saving files. The first time, I was all done with a report after 2 1/2 hours of work and it had been saving just fine. Until I went to print and I got an error message and it wiped my file clean of all my work. Now I am having difficulty saving. Sometimes it saves, sometimes it doesn't. When it doesn't, I loose whatever I did since it last saved. I have had to resort to saving after every sentence. I have tried downloading the original template file I made and still the same. I have tried a different template and the same. So it does not seem to be the files themselves. I  believe I have the latest version on the iPad because I could not find anything allowing me to update. I work in the field and can't have this happen. Please any help would be appreciated!  Thank you.