Named endermite in Minecart despawns

I was making an enderman farm and I trapped and named an endermite (after dying multiple times) and went on to push it in a minecart. The farm worked as intended for about 2 minutes before coming to an abrupt stop. I checked on the endermite, and it had despawned. I went into a creative test world later, and I figured out that for some reason, an endermite loses its given name once put in a minecart. Destroy the minecart, and it gets its name back. But it's impossible to make a secure enclosure for this thing while also getting enderman to see it. Mojang, please fix this.