I am looking for a record according to values of field1 and field2. This really is my query

$rec = RecQuery::create()->filterByField1($field1)
                         ->filterByField2($field2)
                         ->findOne();

$field2 might have strange figures sometimes. For whatever reason whenever $field2 consists of a \ or /, propel can't retrieve the record and returns a clear result.

Basically do that (get ALL records according to field1 only, then loop to complement field2), it works fine and has the capacity to retrieve it

$recs = RecQuery::create()->filterByField1($field1)->find();
foreach ($recs as $rec){
   if($rec->getField2() == $field2)
         //found the record
   }
}

Does anybody understand what the issue is?

Propel should be getting away OK, even when you will find slash figures inside a string.

Are you able to grab the SQL it's running (when you are getting your empty resultset) and find out what the issue is after that? Combine it with your question in the event that does not shed any light onto it for you personally.