[Koha] Zebra problem (?): Search by ccode does not work

Dear all, Searching by ccode does not work on www.bibliotheque-helene.org. Our mrc flavour is Unmarc and ccode are stord in 995$F zebradb$ rgrep ccode . ./biblios/etc/bib1.att:att 8009 ccode ./ccl.properties:ccode 1=8009 ./ccl.properties:mc-ccode ccode ./marc_defs/unimarc/biblios/record.abs:melm 995$F mc-ccode Can anyone sea what's wrong ? Many thanks in advance for any hint, Sébastien.