@emmetbroaders 

The similar issue has been discussed here, with workaround: https://community.tp-link.com/en/home/forum/topic/619564

  @Alexandre. This really just says to do what I've already done though? I can keep unplugging the final node all I want, but eventually it's going to default a couple of days later and I'll have to do it again. Never mind the fact I won't know it's happened until the signal becomes unbearably slow. 

I don't understand why it's only a single version of a single deco that has the programmed ability to do this.

  @emmetbroaders 

It is not just single vesrion of a single Deco model that has configurable connection settings, but S7 is not on the list: https://community.tp-link.com/en/home/forum/topic/614754

Can you add distance between Main Deco and Bedroom unit? Just few more feet/meters could be enough.