Why do my contacts appear in messages but not the phone app? (Galaxy S7, Oreo)

[Android Central Question]

My phone displays all recently contacted names and numbers in the phone app, even if they were acquired years ago, but they cannot be searched for. the only ones available from search or the regular contacts list are my google contacts.

all contacts are searchable in the SMS messaging app, and show up if that contact calls me, so I know the info is on the phone, my contacts list just won't let me look at those.

maybe I need to sync something, but I cant find anything in settings or contacts settings for that.