Usually though wallet explorer will tell if the address came from a trading site, but I'm not sure if it can determine if the address is from a gambling site. Or it they really use wallet explorer to make a trace.
It's the same thing whether its a gambling site, exchange or faucets.
Nope, never experience it but its really weird though, how do they know that it came from a gambling site?
Nope, not that weird, blockchain is public ledger means that there's always a track, some of this gambling sites have a name/tag on their address in blockchain whenever they sent or receive like these addresses
https://www.blockchain.com/btc/popular-addressesEven now there are plenty of reports that most of their users got banned with the same problem as yours you can see it on their fb page and official group, just ridiculous that their support is still shit even their users grow in numbers.