Each computer system may have a different response. But here is a good general rule:

When you checkin for the flight, check with the agent if the AC*G remark appoears and you are recognized as *G flier. If you are not recognized as *G, then have the agent delete your AE#, save the PNR update, then re-enter your AE#. This procedure will regenerate your FFP status and should get you into *G. As a back up, have screen print documentation that you are a new Elite and *G member.