Hi! Lucky for you, I own 8 Pixel Chix. I think I can help you on this one!
Pixel Chix run out of batteries, and quick. Their refresh rate is extremely high so it eats them up within days. This is pretty inconvenient for people like me as it costs them quite a bit to keep on buying and replacing them every few days or so. Last year in March, I bought a bundle of 5 Pixel Chix on the Facebook Market. When we first got them, we had a lot of glitches like you, too. One of the smaller houses as soon as we put batteries in them said that it was low on batteries, so be just assumed there was something wrong with the batteries and took them out. The other smaller house proceeded to show 2 black vertical lines across the screen. After this, I was playing with them for a day or two, and suddenly they just shut down. I couldn't use the buttons, or anything. But, for some reason the light was on in the little window. I was really confused as around 2 hours later this happened to my other one. Resetting didn't work, so we took the batteries out and put them back in, which did the trick.
The reason we think this happened? Well, we are suspecting that the units were left in a cold or damp place and left them corrupted. That is what my Dad thinks, anyways. What also sometimes works is to try and take the device apart and put it together again. I can't guarantee these methods will bring you success, but if these don't work then I would actually try and use a different brand of battery. It will still have to be AAA, but you can find another brand and that may fix it.
