Sometimes it just happens maybe you did something wrong or it does it for some unknown reasonbut most of the time it is no big deal if your tama is working properly
this has happened to me some times too but you have to make sure there isnt a lot of sunlight in the way when you play with them and sometimes you have to make sure you press the connect button at the same time you should try and see if that still happens when you connect them on present.
if someone like your neighbour has a tamagotchi or someone who lives close to you does you are normally connecting with them.so your not connecting with no one.