I really wish that MP would provide a user guide (or guides) for how to make LinkedIn work within MP. For the time being, we’re just left to our own guesses.
I’ve just checked within my own account and dating back to May (I’m writing this in August), MP has sent connect requests to 678 users. So I assume it’s working
Maybe something is wrong with your settings or your profile? If enough people click “I don’t know this person” it can flag your account.