query-errors logging is happening at log level info in BIND 9.11.6
For example: 12-Mar-2019 02:38:14.205 query-errors: info: client @0x xxx.xxx.161.171#26029 (aaa.bbb.ccc.ddd.in-addr.arpa): query failed (SERVFAIL) for aaa.bbb.ccc.ddd.in-addr.arpa/IN/PTR at query.c:7176
This was not happening in BIND 9.9
The documentation of this logging category says that it is for debugging and nothing is logged until debug level 1 (increasing what is output as we go up through debug 2 and debug 3)- but clearly that is not the case here.
When did this change, and is it deliberate or accidental?