Exactly. The first one isn't a GU and there are actually only two GUs from MEP till PPR. The very first update you get right after MEP is an actual update saying that you've passed the medical exam which is also updated in your EE profile along with your UCI.
For post July 2021 PNP-O AORs at CIO, the average seems to be 1st GU (eligibility passed) 5-6 weeks after MEP and 2nd GU (security passed) 2-3 weeks after 1st GU. 60-65 days from MEP to PPR.