FINDFIRST and FIND('-') freeze for minutes on the same records while FINDSET(FALSE) finishes in1sec

So at first i was using find('-') because total records vary from under 10 to 600.000... i dont modify the database , just counting and categorizing them. 1 example had 150 records total and the transaction would freeze for minutes on the exact same two or three records when run for the first time a day ( every following time it would still freeze but for only a second or two. I've tried to do this in a report and in a cu with the same results. Even the records are the same every time. Debugging wouldn't help me because the freeze happens right before the entrance point into the next record. When using FINDSET(FALSE) i don't encounter the same problem. I have also commented out all content inside the loop - same problem.

part of code

      IF l_RSubscrLine.FIND('-') THEN
        BEGIN
          REPEAT
            {code}
          UNTIL l_RSubscrLine.NEXT = 0;   // this is where the debugger freezes 
        END;

Any ideas are appreciated.

Cheers.