You can troubleshoot the slow running queries by using SQL Profiler, Using Extended events. Here is how:
https://redmondmag.com/articles/2013/12/11/slow-running-sql-queries.aspx
You need to know the reason why SQL query is running slow: https://www.red-gate.com/simple-talk/blogs/when-you-really-need-to-know-why-your-sql-querys-slow/