"Most" apps? So it works in some apps, but not others?

Setting your preferred password/passkey manager on Android 17 to 1Password works fine in Chrome and Firefox to log in to any site, presenting passkeys managed in 1Password. It also works in all of Meta's native apps. (I'm pretty sure it works the same in Bitwarden.)

Whatever issue you're having, it's not an inherent limitation of Android passkeys. It might be a bug in your passkey manager…?