Changes in Acrobat for iPad Pro not saving to original location

Whether I open a pdf from OneDrive or Files (iPad Pro 4th through latest) and make changes such as adding comments and highlighting, the changes are supposed to save automaatically to the original location but they do not, at least not right away. I would have assumed that the "Back" button would save to the original location, but sometimes it's hours later and the changes still have not saved. This is extremely disruptive to my work flow (research and writing) because I have to be able to move seamlessly from iPad (for example when reading and annotating on the go) back to my desktop for the actual writing, and I end having to go through this whole process of saving a copy every time I make changes so I end up with a bunch of files where I only want one. It's really a rare instance of poor designh in Adobe. There should just be a straightforward save button so that i can execute a save, close my iPad and continue on another device.