Yes, I am using the latest version (Release Build 867 - 2017.03.02.44979 (x64)).
I maybe was too hasty to claim that arbitrary expressions containing ? would fail, however my main use cases were to discover files who either contain at least one question mark - "?" or "<?" and both of them seem to match all alphanumeric characters, instead of just the question mark or the "<?" group, even when enclosed in quotes.
I can work around this using regular expressions with an escaped question mark - \? but it seemed very odd that I couldn't use normal 'boolean' matching.