It doesn't like how you have something configured. The error message provides indication of such. It is pointing to your private upstream section. Not the main part where you have placed your Google, cloudflare, and quad9 at.
Please check out posts around this thread.
Sorry I think I am not being clear. I am not talking about local logging of queries. I am talking about at the DNS provider level. Here is another way to look at it, if the only cloudflare server near your geolocation goes down; and, you are using that cloudflare server you may notice a service...
www.snbforums.com
Basically, You have a non-local arpa listed in the Private Upstream section. Only arpas for private ranges can be specified there, (e.g. 1.1.168.192.arpa).
AdGuardHome has determined that you have an arpa for a non-private address range listed in this section. In order to use a non-private address arpa, you must specify it in the same upstream section where you listed these lines: