Show valua but cant change it to bnb


I have a question my trustwallet shows i have xrp.
But when i wanna change xrp to bnb it shows valua 0.
I tried before and it asked me to approve my xrp so i did it. But still it shows 0 valua. Also i have 2 wallets and it showed also the valua in 2 wallets but i cant do anything with it.