Your AI would be able to function like Humans
Considering that humans may already have some forms of self-imposed$_1$ mental block ranging from "really don't want to think about it" (e.g. visualizing certain people naked, specific unpleasant memories), to "physically unable to think about it" (e.g. certain phobias, traumas, etc). Being unable to think about specific things is probably not a disqualification of being human.
So an AI with similar arbitrary restrictions would not be prevented from passing as human. Rather they wouldn't even be required to know they were an AI, and might just be seen as humans with peculiar predispositions.
They may appear weirdly dedicated to their job$_2$, but not inherently suspicious without additional intervention. Effectively they may just be considered as humans with a few specific mental pathways built in.
(And if, over time they may develop new neural pathways, unconsciously rewiring their brain to get around the block, then the question becomes moot anyways)
$_1$ Self-imposed as in coming from the brain, not necessarily conscious decisions.
$_2$ This is assuming their primary work focus allows for downtime, either during the process (the nature of work they're phsically doing doesn't require 100% cpu), between process (i.e. while waiting on another system to complete it's task), or mandatory adherence to local labor laws.