Does Google Drive Integration only get new and future submissions?

I set up Google Drive integration for my forms to feed into my Google Drive. It is working for one form and not for the others. The one that is working is one that I had integrated immediately upon creating the form before there were submissions.  The 4 that are not working are ones that I had integrated much later after there had already been submissions. Could this be why? Would it not feed earlier submission to the folder too? Is it only set up to feed submissions that occur after the integration?

That's correct - The Google Drive integration will only start getting submission data and uploaded files after enabling the integration. It won't fetch the existing ones in your form.

In case you have other questions, please don't hesitate to ask.