When I open the game either in the Epic games launcher that I bought it in or in the Ubiconnect program I get the window for battleye starting up and synchronizing achievements. Some might work for you as others have said I hope you all can share some ideas with me also Thought I would document my attempts some my ideas some from forums ubi etc and reddit.
I have been trying to launch riders republic for about 9 hours now 4 yesterday and 5 today.