[otrs] Search issue in otrs6

Hi, There's another difference between otrs5 and otrs6 in searchs. In otrs5 when we did a fulltext search it looked at subject, from, to, etc. It was so easy (and a bit slow) for agents to do a simple search without specifying more filters. Now it works different, and I still don't know how it works, but if I know that I'm looking for a ticket from somebody  with a known name, the best way to look for it is using "Customer ID (complex search)". Can you please explain me the differences between the fulltext search in otrs5 and 6? Excuse me if it is already documented, I have not find info related to this question. Moreover, is the behaviour of the fulltext search configurable? Regards,   Manuel Martínez