LDAP auth not working on new server (V12 with php8.0)

Hi colleagues,

we have an issue with LDAP auth. We upgraded a Sugar from 10 to 12, and installed the upgraded version on a new server.

the server is a debian-like linux, we installed php8.0 with appropriate packages (included php8.0-ldap)

cli command auth to LDAP from the server works.

Sugar succeed to reach LDAP server, but LDAP answers with "ldap error in order to perform this operation a successful bind must be completed on the connection"

connexion from old server still works.

is there any configuration/package that I could have missed to make it work ?