Cannot enter BIOS after trying to fix bootloader after windows update

I have both installed windows 10 and ubuntu on my PC and usually I get the boot (grub?) menu when I start my computer. But after a windows 10 upgrade that menu is gone it just boots windows 10 directly. I have then googled on how to fix that problem and found:

Fix a grub after windows update

which suggests:

bcdedit /set "{bootmgr}" path \EFI\ubuntu\grubx64.efi

or

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

That did not fix the issue and further it has also removed my BIOS splash screen on startup showing the keys to press to enter BIOS etc.!

So:

1. How do I get my BIOS splash screen back again - and the ability to actually enter BIOS?
2. How do I fix/re-enable the multiboot menu so I can boot Ubuntu again?