Google Analytics Discrepancy Question

Can anyone tell what has caused this?

"The Ad Destination URL ____ from the AdWords account _____ has accrued a significant number of clicks but a lower-than-expected number of sessions. After analysis, the tracking code on the page appears to be correct. Check the page's latency using the Google PageSpeed tool. Also check your keyword-level, ad-extension and merchant center feed URLs for proper tagging if they are present in your creative or campaign configuration.

Google Tag Assistant Recordings can help you ensure that your Google Analytics tag is firing with low latency."