I don't get it: Godaddy Auctions & Page Rank

So I bought a domain name from Godaddy auctions that showed PR 4 in Scrapebox and also PR 4 at the Godaddy parked expired domain website while it was on auction.

Now that I got it, it shows no PR at all.

Can anybody explain that to me? Does that mean it doesn't make sense to grab an expired domain name that shows high PR? Does PR get wiped out when it changes the owner?

Thanks in advance for helping me understand why

scrapebox has an add-on that checks for fake PR, shoulda used that over the other one.

If you use scripts or SEO software without proxies you might be blocked... check PR from someone else's internet connection like a coffee shop or from work or something.