EF, why is the select query running so much slower than usual?

Question

SQL

Kind ))
Task: Last week the task was to attach server pagination to one report.
Used by:
MS SQL
.Net
Entity Framework
Web Api
Problem: The data fetch query is very slow.
Solution: first I checked this query in SQL Management and it turned out that it works slowly here too, and all because there are no indexes in the database. I added indexes and, lo and behold, the query was executed instantly both in SQL Management and in the application.
The task was solved, but when I returned to work today, I decided to double-check, and found that pagination in the application was again slow, but in SQL Management it was fast.
I decided to write in detail, because I think I made a mistake somewhere. What could be?
Thank you.

Answer 1

Turn on profiling and see what happens.