Download files are being set with automatic passwords not assigned by me.

There must be something in a setting that causes this. I know for a fact this is not something I'm choosing or the author has done. I get Docusign documents regularly and if i open it and save it it will be locked when i go to reopen it. The only way I can save these files is by directly downloading them to a file or my desktop then reopening. Why does this happen?

Thanks in advance, Todd