This is one thing I have noticed when adding observations to projects. You have to add all observations to a project manually. I was wondering if there is an existing way to add all suitable observations to a traditional project at once.
I had a situation where I wanted to get both individually added observations from a traditional project and a geographically defined collection project into the same project. I started an Umbrella project and that worked great. I suspect an umbrella project is also what you need.
Still manually, but not one by one, see:
https://forum.inaturalist.org/t/bulk-selection-of-observations-to-add-to-a-project/1747/58
Here’s a help page for the batch edit functionality as well: https://help.inaturalist.org/en/support/solutions/articles/151000195590
Yes, two thumbs up for the batch edit functionality. It’s great. For traditional projects that require (or recommend) observation fields, you can also use the Batch Edit to add fields to a selection of your observations.