[Maria-discuss] Maybe OT: we have clients from Centos 7.8 sporadically connecting via 'strange' ipv6 address

Hello, do not know if this is the right place to ask, we have, since updating to Centos 7.8 from 7.7, some PHP Webs which try to connect to the MySQL server with the following IPv6 as address in the addresspart of the user: 'user'@[::ffff:10.11.12.13] They get access denied as the real user is 'user'@'10.11.12.13'. Is this a PHP problem or a MySQL client setting i can set to disable this IPv6 thing? Disabling IPv6 on the interface can be done but I'd rather would not. Regards, Thomas