The minimum of characters used to search on is 3
So 99 is not sufficient to perform a search on
You can do:
min AND cdr
this will maximize your search results.
And if you know for certain it has been the title of a topic, you can select the option 'Search in titles only'
btw only found '90 min cdr' and '80 min cdr' topics when searching on aforementioned option.