[Pebbles82]

Is it the Barney or Alexander cage by any chance? I think an upgrade will be fine once they have settled and they might need a bit more space. You'd just have to do the changeover carefully. I believe it is quite common for a pair to fall out even if they aren't moved, and often when hormones kick in, but there are successful pairings as well. One thing I read (not science here, just opinion) said that it can even be as much as taking one out for playtime but not the other, that can start territorial behaviour. So that might be something to bear in mind.

If you want any tips setting up the 100cm cage when you're ready to move them, then come on here first maybe. There are people on here with large set ups for dwarf hammies who might have some tips. For robos I think you need lots of overhead cover and floor toys and no too much open space, lots of hidey places, plus deep substrate and a set up that avoids fall risks.