if u have uninstalled ubuntu u can try to fix ur mbr boot. i had the same problem and needed to make a secureusb and than boot from this usb and repair my mbr. after that windows loaded normal.
Jans right try the fix mbr commands
you can repair and rebuild your mbr that way and save
yourself some headache.
See this too brother: How to fix Windows 10 boot loader from Windows
that is spacifically about that "grub" issue you mentioned.
You can google the MBR repair commands I cant recall them off the top
of my head but they have saved me more than once over the years.
Good luck Gamez, let us know how it goes, PM me if you need any help.
PeAcE
Did you reset your BIOS settings to default? Factory resetting will not reset your Boot OS/Mode, it may still be attempting to run "Legacy" and "Other OS" rather than Windows in Secure Boot.