I've had a Ryzen 5 3400G 8 months or so and it has always been SLOW to boot to windows 10.
I had it on a AsRock board and just swapped to a MSI B450M Pro-M2 and it still take a few minutes to boot up.
What is going on???
Do you have a lot of 3rd party programs starting up?
That would make your computer slower to boot up to Windows completely since it needs to start all those 3rd party programs in the background.
Also go to Event Viewer and look under "Error" and see what type of errors are occurring.
One way to see if it is your 3rd party programs start ups that are causing the long boot process into Windows Desktop when Windows boots up is by booting into a Clean Windows desktop.
It is simple to do and only Microsoft programs and drivers will be booting up. here is how to do it: https://support.microsoft.com/en-us/help/929135/how-to-perform-a-clean-boot-in-windows
If Windows boots up fairly fast with a clean Windows desktop you can start enabling half the disabled Start up programs and see if it boots up much slower. That way you can narrow down the Start up App that is causing Windows to take so long to boot up.