Ultimate Cron Background Process Taking a Long Time
I think we need to check from start to end point. This issue is like some processes which takes more time to execute. So we need to check what is that process and we can find that using Elysia Cron plugin.

This plugin helps you to find which cron process has taken much time and where to take possible actions.

PS: If this stuff helps you please leave me a comment and support :) 

Thanks!