On the linux side of things, people like to manually edit /etc/resolv.conf when it’s actually a symlink and changes to it don’t persist on boot (the real file location varies, but it’s usually in something like /etc/system/resolve). And forget bind9, if it’s not MS DNS it’s not DNS to some folks.
On the Windows side, people love to ignore that reverse DNS exists, even though so many things use it. They also freaking love CNAME aliases and break stuff in interesting ways (for example, a “load balanced” configuration that’s all just the first node acting as all three nodes of a cluster or pool).
Many people only know enough DNS to be dangerous and come up with really jank workarounds to get things running because they don’t understand the proper solutions.