Well, it may take a bit of time. Usually for me maybe a couple of seconds
because I have used it often and have therefore plenty of peers to chose
from.
I would wait a bit longer.
P.S. I do not use the GitHub version, I use from bitmessage.org
it actually throws an IndexError exception after a while that might be halting peer enumeration
i'll have to visit bitmessage.org but usually projects just package git tags