pfSense

I tried on 2.3.3-DEVELOPMENT and 2.4-BETA and cannot reproduce this. If I put a valid name, then it gives me ip=1.2.3.4 the address of that name. If I put an invalid name then I get ip=name.that.i.entered.com

What are you entering for Hostname to get this to happen?

Do you have a 2.3.3 or 2.4 system you can try it on? Maybe it is already fixed.

With 2.3.2 whatever hostname I query the urls are appended with Array. I'll try to setup a testing VM

I got onto a production 2.3.2-p1 system and yes, it has that bug.
I expect it was fixed for 2.3.3 and 2.4 onwards by https://github.com/pfsense/pfsense/commit/7829c6d521f9c19773486b72ee74566b2991e9fc and subsequent changes to diag_dns.php

ok, thanks for checking