User Profile Sync status stuck at “Synchronizing” every time it runs

We have SharePoint 2013 and every time it runs, that status remains on Synchronizing although it is importing user profiles. In order to make it idle we do the following:

1. Click on Stop in Central Administration the screen will show stopping for the Profile Synchronization Status

2. Reboot the server than runs User Profile Service (We tried to restart both FIM services from services.msc console, but that did not work)

This happens every day. I am not sure why this is happening and how to fix it. I did look at this article, but that did not help:

User Profile Sync status stuck at "Synchronizing"

Any idea how to troubleshoot/fix the issue?