[Koha] Cannot find records created in KoHa

[Lichtsteiner Patric (lici)]

Hi,

I guess this is a very basic and silly question.

I just created my first record with some items. Among other things I filled in the field "Number (ISBN)” with 100.100.

Using the advanced catalog search I’m trying to find my record, but nothing is found:
No results match your search for 'nb: 100.100'.

What did I miss?

Best,
Patric