[Koha] Authority search in SEE FROM TRACING (Field 4XX)

Hi all I try to use authority records. Searching the controlled terms (in 1XX) works fine. (I had to change "Heading-Main" into "Heading" in C4/AuthoritiesMarc.pm to enable it) But I'm not able to search for the "SEE" references (Fields 4XX). My example: The record with: 100 1# - HEADING--PERSONAL NAME a Personal name Davidov, Carol Julevic d Dates associated wit 1838-1889 400 1# - SEE FROM TRACING--PERSONAL NAME a Personal name Dawidow, Karl Juljewitsch is found if I search with "Davidov", "Carol" or "Julevic" but not with "Dawidow" and so on. How can I make these terms searchable? Greetings Beda BTW: Chronological Terms can't be searched at all.