I have a Mini PC (I think I “reviewed” it here one time) that is running a AMD 2400G which appears to be 2nd gen Ryzen but is actually first gen and not supported 
The mobo on it could take a 3400G, but they are hard to find and very expensive now that the 5600G and 5700G are available (but unsupported by the mobo.)
Edit: This is the “review” of the one I built with a 3400G (I built two within months of each other.) A review, of sorts, of the Asrock DeskMini A300