The following happened for a second time - escrow order is made(correct address info) and marked as sent soon after. The items don't arrive on time, upon inquiry vendor says its all good on their side. After a few weeks - nothing, and I get btc back, because it was "vendor's mistake".
Is it common for people to try and cheat you out of your money, counting on the chance that it AF? And both times I got full refund - is this the usual DNM practice or am I lucky?
Did you dispute and get the BTC back through the dispute process or did the vendor release the BTC?
It seems to me like you should probably do a little more research on your vendors. Twice could be a coincidence, but if it happens again something is wrong on your side. However, it doesn't really sound to me like vendors are trying to scam you. It is possible that for some reason they don't want to ship to your address. For example, if you're shipping to a police station.