I have the same outcome,on my geneology I have a lot of Affiliates who haven't logged in for some time,I lust keep sending Teammail to them,you just got to keep in contact so when they eventauly log in the team mail is there.I also believe that some of them might have to get to a E cafe,which could be awkward for them
the next time they are able to log in,could be the next Affiliate to hit Platinum