inconsistent usage schedule
That would mean that the system in question might be suspicous that you might have shared your account. Like being online for 20 hours a day. Itch does not have things like that. Streaming services might.
But Itch does have some triggers, that will, in combination, make the system suspicious. Obviously, connecting from different computers might trigger this. Using a vpn. Travelling. Or, of course, sharing your account. Which makes little sense for Itch, but I have seen a developer team do that.
I got hit by "supcious activty", when I tried to access Itch while it was down. But only partially down.
There is even an obscure thing that might happen for some people: there is bot networks on hacked devices. There are even cheap devcies sold pre-hacked. Not kidding. If those networks were used to facilitate attacks, ip adresses might end up in a temporary block list. While I have doubt that is is happening for Itch, those bot networks are real and there are devices sold that are already hacked. It just is an example that there might be reasons for things, that one would not think of.
Anyway, https://itch.io/t/4120453/unofficial-search-and-indexing-faq
Any update can trigger a temporary delisting. And if you have to wait for staff to have a look, that can take over a month. I see one update less than a month and an accound only 1 1/2 months old. Not much out of the ordinary yet. Itch is slow. Sad, but that's how it is.