Each Windows 10 release modifies the bootloader.
Each Windows 10 release modifies the bootloader.
It seems like you're experiencing some inconvenience with the system. Trying safe mode and rebuilding the bootloader is working, but it still bothers you each time.
People are facing problems with their bootloader after a Windows 10 update because several factors could be involved. It might relate to how partitions were configured, whether the system used UEFI or Legacy mode, or differences between Windows 10 and Linux setups. The issue seems specific to Windows 10 and Linux but not necessarily to Windows 10 and Windows 7. Your setup involved a new SSD, two partitions per drive, and switching between Windows 7 and Windows 10 installations. The MBR remained stable during updates, yet Windows 10 had problems with certain versions, requiring a full reinstall from scratch.
UEFI operates by having specific entries that reference certain EFI files, which act as bootloaders. Windows typically places its own entry at the top. Solution: A tool can adjust the Windows UEFI entry’s EFI path so it points to GRUB’s location, as indicated in the GRUB entry.