When I try to run the following query:

FROM Table
WHERE Contains (*, ' "market closed" ')

I am returned rows that contain the whole phrase and also the rows that contain either "market" or "closed" words.

I have a strong feeling that indexing service does not work as it's supposed to work. I have a change tracking option with background indexing option. Every night I delete several records from the table. I do not do full population after deleting. I have done full population only once when creating a catalog.

if you need any additional info to resolve the problem, please let me know

Thanks a lot