[Koha] search patron not working

[Giuseppe Angilella]

Hi,

I am using Koha 22.05.00.000 on Ubuntu 18.04.6 LTS.

Since a few (Koha) updates ago, I've noticed that the "search patrons" 
function is not working.

I type in the first letters or the full name of an (existing) patron, the 
search engine starts, but no one is found.

In order to display the patron's details, I have to look for an item 
he/she certainly has borrowed, and click on the patron's link in item's 
"Status" tab.

Any hint?

Many thanks and best regards,

Giuseppe.