Can't see all characters

Hello. I am trying to 4 box in WOW Classic. I run the set up wizard, save my setup and log into WOW on the four accounts. I can see accounts 1 and 2 together. I can also see accounts 3 and 4 together, but 1 and 2 can not see 3 and 4. Does anyone know what I am doing wrong or how to fix this?

Thank you.

[bob]

I believe this has been answered on discord, but for reference to anyone else, this is the result of in game layering, and the answer is to invite all toons to the same party.