I see 8 observations deleted via the iPhone app on July 6th around 9:45am Eastern. Since there are just a few observations, and it sounds like you have the data still on your computer, the recommended action would be to just re-create the observations.
While iNaturalist is a good place to archive observations, I just want to point out we are not to be used as a photo backup (see https://www.inaturalist.org/pages/what+is+it), so I recommend you keep copies of all your photos.
Did you not intentionally delete these observations from within the app? Would anyone else have access to your account via the iPhone app? Or can you think what else may have happened yesterday at 9:45am EDT?