Proxy cache not work with <attribute not in schema>

slapd 2.4.40 Windows AD as proxy backend.

I found any query match <pcacheTemplate>+<pcacheAttrset>+<attribute not in schema> will answer <pcacheAttrset> value only, <attribute not in schema> will be ignored. This is not what I expected, I need <attribute not in schema> too.

But query anything else that not in cache, <attribute not in schema> will be cached. Log message like this: 580ec506 PROXIED attributeDescription "PRIMARYGROUPID" inserted.

And after that, query match <pcacheTemplate>+<pcacheAttrset>+<attribute not in schema> will answer <attribute not in schema> too. This is what I expected.

Do I have to add schema for <attribute not in schema>? Is there any other way to make <attribute not in schema> CACHEABLE?

-------------- JWD