Nissa of Shadowed Boughs Vanguard Bug [Investigating]

Nissa of Shadowed Boughs's Static ability reads: 

"Landfall: This support gains 1 shield."

Nissa of Shadowed Boughs's +1 ability reads:

"Target creature you control gets +3/+3 and gains Menace until end of turn. Then, convert 3 gems to that creature's colors."

One ability is not dependent of the other. However, if you use this vanguard's +1 ability you cannot use it ever again until a Landform happens (it can be yours or your opponent's but it has to be a landform). To make it more weird, if you use the +1 ability and then you match 5 gems during your turn, since 5 gems count as a landform you can use the +1 ability again in the extra turn granted by the 5 match you previously made.

You can watch all those interactions in the following video:

https://www.dropbox.com/s/06z26gf3iemskti/Nissa Of Shadowed Boughs Vanguard Bug.mp4?dl=0