Very interesting. I believe that sometimes Native American genetic markers have been confused for East Asian due to the more recent shared common ancestry between those two populations, and Eastern Europe at least was invaded by groups like Huns, Tatars, Mongols, Cumans, and other tribes from Central/East Asia who would've been at least of partial East Asian heritage/appearance. I've seen the occasional Russian, Hungarian, etc. with somewhat Asian appearance and perhaps what's showing up as Native American is actually a very slight remnant of something like that. I'm just speculating and could be totally off here but that's my guess as to how an Eastern European/Italian-descended person would show Native American ancestry.

There's a female Croatian tennis player (I forget her name) who actually looks like she's half-Asian. Very rare appearance for a Croatian obviously, but people like that occasionally pop up in Eastern Europe from time to time due to the history of eastern steppe tribes traversing these regions.