... or it maybe may be. I’m not sure I fully understand the subtle difference. If I wanted to warm someone I wasn’t going to make an appointment on time, I’d write “I may be late.” But what if I wanted to ask a potentially silly question? Would it be “This maybe a silly question...” or “This may be a silly question...” Maybe doesn’t sound right but I don’t know.
Think of it like this: "be" is a verb. "may" in the case of "may be" is a modal auxiliary verb, expressing possibility. "maybe" as one word is an adverb. So you can't say "This maybe a silly question" because that sentence is missing a verb. You can say "This is maybe a silly question", although IMHO that phrasing is a bit awkward. "This may be a silly question" would I think be most grammatically correct.
I think a common acceptable phrasing of that would be "Maybe this is a silly question". In this context, 'maybe' is the same as 'perhaps'.