Howdy @crysist8688! If I may, I'd like to give you a big, warm welcome to the official Ubisoft Forums! I'm sorry to see that you're having this trouble playing Assassin's Creed Valhalla following the purchase of Dawn of Ragnarök! To begin, I'd like to mention that while the game may run using the Windows Insider Build, such a build of Windows isn't officially supported for our games. Having said that, you can still try our basic troubleshooting to try and improve the computing environment for the game on your computer.
Also, I recommend that the game and the Ubisoft Connect game launcher are installed on the same drive together on your computer (if they're not already). Preferably the two programs should be installed on the same drive as the operating system (Windows). Thanks for working with me, and please let me know how this goes!