I was recently working on a PoC and I was trying to get the information in the Experience Profile. After few hours, I realized that even after browsing pages in different browsers, my contacts weren’t showing up in Experience Profile.
The Sitecore Experience Analytics was showing me the data which meant that the xConnect was working as expected. I started to do some research that if my analytics piece is working as expected i.e. I can see my views in the Analytics dashboard then why am I not seeing the contacts in the Experience Profile.
To my surprise, by default the anonymous users are not indexed in xDB and that piece I missed to enable. So if you want to see the contacts in Experience Profile which are Anonymous then you will need to enable below setting in sc.Xdb.Collection.IndexerSettings.xml file (Path: C:\inetpub\wwwroot\{xConnect Website}\App_Data\jobs\continuous\IndexWorker\App_Data\config\sitecore\SearchIndexer)
<IndexAnonymousContactData>true</IndexAnonymousContactData>

Now you will need to rebuild the xDB index, you can do it by following the steps in this blog.
Once you rebuild the xDB index, you should be able to see the Anonymous Contacts in the Experience Profile.

Hope it helps!
Thank you.. Keep Learning.. Keep Sitecoring.. 🙂