This is a mint error, Peter was right.
It's a nice coin with an interesting story, coin is known among romanian numismatists like "HORA" ( circular dance) in fact , obverse side represent the Great Romania Allegory. Mother Romania regains her daughters Basarabia, Bucovina and Transilvania,alltoghether returned to Motherland in 1918 at the end of WW I.
Source of inspiration for this obverse side of the coin was a work of art in white marble "Union Monument" in the city of Iasi , made by Princess Olga Sturdza (sculptress) in 1924. Monument was destroyed after 1944 by communist authorities and rebuit after 1989 to initial parameters.
Coins of King Mihai I circulated very little time, he was dethrowned by his father King Carol II in the same year -8th June 1930. Personally, I think not all of them circulated due to this short period of time and many of them were melted, it's difficult to find this coin in very good conditions, about UNC ......

There was a total of 50.000.000 coins struck , at London Royal Mint 40.000.000 - with no mint mark, 5.000.000 at Birmingham King's Norton Metal Company with KN mint mark and 5.000.000 at Birmingham Heaton Mint with H mint mark.
https://en.wikipedia.org/wiki/Union_Monument,_Ia%C8%99ihttps://www.google.ro/search?q=20+lei+1930&tbm=isch&tbo=u&source=univ&sa=X&ved=2ahUKEwjTv-3z1OLeAhXCccAKHXOxC-MQsAR6BAgDEAE&biw=1592&bih=772