Hi kristijan209,
Thank you for using the Apple Support Communities! We understand the emoji keyboard seems to be defaulting to the Smiley's & People section, while you prefer to see the Frequently Used section first. We'd like to help.
Testing this on our device, the emoji keyboard should remain on whatever section you last left it on, even after exiting the application you were using. Meaning, if you open the emoji keyboard in Messenger, slide to the Frequently Used section, then exit the app and come back in, you should still see that same section appear when reopening the emoji keyboard.
Since it sounds like this is not happening for you, we have a few steps you should consider trying, to see if it helps improve your experience.
-Force quit your affected applications: How to force an app to close on your iPhone, iPad, or iPod touch - Apple Support
-Restart your iPhone: Restart your iPhone - Apple Support
-Make sure you have the proper keyboard selected under Settings > General > Keyboard.
-If you have any third-party keyboards, try uninstalling them temporarily to see if that is impacting your experience.
-Consider updating to the latest iOS, and make sure your apps are also all up to date: Update your iPhone, iPad, or iPod touch - Apple Support and Update apps or use automatic downloads - Apple Support.
Keep us posted if you need continued support.
Regards.
