Issue #1: If you run low on storage while coping photos results are unreliable, which may be expected. Some, perhaps many, files will not be uploaded. And why was I low low on storage? Because the app creates a temp folder with copies of the photos you are copying. I had over 600MB in this tmp folder which filled my storage and caused the app to be unreliable without warning. I'm sure it's much less of a problem in day to day usage, because a much lower volume of photos are likely to be transferred. However when you just start using the app it doesn't back up existing photos. So if you need to copy... Share , a large batch of existing photos you may find yourself in this situation.
Issue #2: I selected 17 files using a Android file manager then shared with nextcloud…only 5 were transfered. Tried multiple times always 5. But when I shared same 17 with the Gallery app they all were transfered.
So why didn't I fill out a bug report? Because every time I filled out information...they wanted more. Finally, when they asked for logs, and told me to make sure I didn't include sensitive information I gave up, because I'm not going to comb through all that data looking for a needle in a haystack. I'd probably miss something. Anywho...I understand why they ask for it and knowing what I know, I pretty much can work around the problems.