ODK briefcase only exporting a percentage of submissions

1. What is the problem? Be very detailed.
I've been able to pull all submissions from ODK aggregate server into my folder but unable to export all submissions.

I was able to do everything perfectly with one form, but unable to with two others. The export status simply shows "Exported 22% of the submissions" and "Exported 181 from 583 submissions". Why is this?

2. What app or server are you using and on what device and operating system? Include version numbers.
Windows. I've tried this on both ODK briefcase v.1.15 and v.1.17.4.

3. What you have you tried to fix the problem?
I've tried using a more updated version of ODK briefcase. I've tried troubleshooting: clearing pull history and reloading forms from storage location.

Thanks in advance!