new cage and they start to fight again

[koen minschart]

hello when i bought my female and my male

they were in a small cage but they were fighting. so i used the split cage
method and after a week i placed them in a bigger cage. the fighting
stopped.

today I went to the petshop for an even bigger cage with tunnels
outlookposts... and they started to fight again.

it seems like everythine the have a running weel they fight

any suggestions???