Seeing as your canadian...
Newer coins ring up as iron on my machine. So if I want to find them I have to dig everything... does your machine ring up newer coins as iron? Maybe I can notch out a little bit of Iron ans still get the coins.
Test that 18k ring immediately. There’s a scam going around at parking lots, gas stations, casinos, etc where these are being offered to unsuspecting people by scammers who “ran out of money”. I see at least one a week that’s marked 18k and is fake and they all look similar to yours. Keep us posted.