Wandering dude won’t grow strong roots

Hi! Just like the title says, my wandering dude won’t grow strong roots! I have never had success growing these, so I have tried to propagate my last one that was dying. I’m using a grow box with perlite and water. The leaves are growing beautifully but the roots themselves are so thin and fragile!! They are in bright indirect light, I open the box for about 3 hours every week to let them get air then I mist them again with warmer water but I make sure to not oversaturate them. I also use rain water to water them!! What can I do to help the roots? Should I add rooting hormone??