Clicks and Sessions are different metrics, so they should not be compared to one another. A session in Google Analytics is defined as a group of interactions one user takes within a given timeframe on your website and can be as short as one minute long to as long as four hours. For instance, if a user clicks on your ad once, clicks the back button, then clicks your ad again, two clicks will be registered in the ads manager, whereas Google Analytics will only register one session.
For more information, please see this support article from Google's help center, which outlines the definition of a Session.
Please note that third party tracking is outside of our support team's area of expertise. For questions about Google Analytics or troubleshooting requests, please defer to the respective partner's support team.