I also just tried accessing it and as WillyAp said, it's offline. But this alone is enough to show that this is most likely a scam, it is an old scam that has been around for a long time. And as you said you transferred money to that wallet? I'm really sorry, you lost your money and there's no way to get it back.
What I'm more curious about is that from your profile, you've been in the market since 2017, which means you're not an inexperienced newbie. I don't believe that someone with as much experience in the market as you could fall into these traps so naively. Besides transferring money, how can you easily give your identity to unfamiliar websites you've never heard of? Why don't you do your research or ask someone for help before doing KYC or transferring money?
There are legit sites too that experience the same issue of being offline. It's only normal but they try to fix it as soon as possible. There are still a possibility that those who don't came back to life are scams that either have been busted out, or they already reached their desired quota.
When it comes to these things like there is a rule about sending money first, I'd be very wary with that and better to do enough research first, to see if they are truly legit or not. You got a point there about his experience. It's shady and it is possible that he is only shilling it to trap anyone else. Tactics like this are not new in the forum, that's why I know.