That's like asking if there are bugs in a garden.

The problem is that your question isn't clear and it's not enough to try and guess what you mean.

Is there a bug in Itch's HTML code?

Is there a bug in Itch's dashboard?

Is there a bug in Itch's web server?

Is there a bug in the Itch application?

Is there a bug in one of the 2 million projects that Itch hosts?

Besides, bugs will always appear, so you need to be clear about exactly what isn't working, exactly what you're trying to do that isn't working, and if it's a project, provide the name or a link along with a clear description of what you want to ask. 
And if it's about a specific project, it's best to ask at the bottom of that project's page.