Running that site through scamadvisor (http://www.scamadviser.com/check-website/pnsrn.su) shows that it was made 2 days ago and almost all the details about the owner and site info are hidden. It's a pretty obvious scam. PLEASE DO NOT CLICK THAT LINK!

And be wary of random invites that come from private profiles in general.

I have this same issue. Idle Master, for me, doesn't update playtime when idling multiple games. It seems to idle 30 games indefinitely. I have tested it twice so far, and each time I got the same result: Idle Master idles the games but their playtime in idlemaster does not update which leads Idle Master to just keep idling the 30 games without switching back to individual mode. I currently have 60 something games with over 20+ hours of playtime due to idling that didn't drop cards because the cards don't drop when you have that many going at once.

As soon as I restart idlemaster or change it to individual mode only, it starts to work as expected again, and the cards start to drop as normal.