I have a tamagotchi connection v2 and on all of the character charts I've seen, it doesn't say an Ichigotchi can't evolve into a robotchi, but my v2 did, is this a glitch?
This isn't a glitch. It is possible for an Ichigotchi to evolve into a robotchi as they are both found in the even generations.
Riven's growth tamadex is the most comprehensive I have found but it doesn't cover all possibilities. I have experienced evolutions that haven't appeared in them.