https://wccftech.com/monster-hunter-rise-wont-feature-cross-play-or-cross-save/

If you were banking on bringing your Monster Hunter Rise character progression from Switch to PC, or perhaps you just wanted to play with a friend who only plays on PC, it seems you're out of luck. A few hours ago, CAPCOM confirmed in a tweet that cross-play and cross-save functionalities won't be available for Monster Hunter Rise, as the developers looked into implementing them but couldn't do it.

We’ve heard your requests for Cross-Save / Cross-Play for Monster Hunter Rise & Monster Hunter Sunbreak, but unfortunately, after looking into it throughout the development process, we found we are unable to implement it this time. As always, we appreciate your continued feedback and support.