Since I read on https://live.sovryn.app/origins There are known issues when using MetaMask with SOVRYN.
BabelFish recommends Liquality as the best wallet for multi-chain operations https://liquality.io/. They say FISH is already a default token on RSK and XUSD should be added soon. Well, surely they suggest the best for their community, but the choice is still remains in the hands of each.
https://twitter.com/babelfishmoney/status/1430575706510028810