I have a number of DW7 systems including cloud where Index Filters are used, and FullText Search works just fine.
Possibly, your Filter is not set up correctly (for example your Approver names are different from user login name. I suggest you use a simple filter with a static value that you can easily see and control.
Also, I notice that your Index Profile is not set up the way Docuware recommends it: you should have two separate profiles, one (non-IF) with all the rights you want to give users (such as Display, Edit, Edit Index data, append - whatever user need) - BUT no SEARCH right. And the 2nd profile with your Index Filter set and only right SEARCH assigned). And you assign your users to both of these profiles.